BIENNIAL INTERNATIONAL WORKSHOP ADVANCES IN ENERGY STUDIES ADVANCES IN

5th BIENNIAL INTERNATIONAL WORKSHOP ADVANCES IN ENERGY STUDIES ADVANCES IN ENERGY STUDIES PERSPECTIVES ON ENERGY FUTURE PERSPECTIVES ON ENERGY FUTURE Porto Venere (SP), Italy 12-16 Sept. 2006 BOOK OF ABSTRACTS Energy and Environment Research Unit Department of Chemistry University of Siena Via A. Moro – 53100 Siena (Italy) www.chim.unisi.it/energy/ www. chim.unisi.it/portovenere/ Life cycle impacts and total costs of present and future photovoltaic systems. State-of-the art and future outlook of a strategic technology option for a sustainable energy system Paolo Frankl Ambiente Italia (paolo.frankl@ecobilancio.com) Are photovoltaic (PV) systems a viable sustainable technological option for the future world energy system both in economic and ecological terms? The present paper provides a clear response, by addressing the following four main research questions: i) What is the expected technology development pathway of PV systems? ii) What is the expected evolution of their direct costs? iii) What are the life cycle impacts and deriving external costs of present and future PV systems? iv) Which diffusion scenarios can be envisaged? The paper summarizes the preliminary results achieved in the Integrated Research Project NEEDS - New Energy Externalities Developments for Sustainability, a research project co-financed by the European Commission (2004-08). At present the PV market is dominated by crystalline-silicon (c-Si) modules (roughly 90%, including ribbon c-Si). The paper shows that the life cycle impacts and external costs of present state-of-the art PV systems are already low, in particular much lower than the ones of fossil energy sources. Moreover, in the long-term future the PV technology spectrum will be very different from the one of today. By 2040, cSi is expected to account just for 20% of the market, while the rest will be equally covered by thin film technologies and 3rd generation devices (i.e ultra-low cost, low-medium efficiency cells and modules, and ultra-high efficiency systems). All these future systems will have significantly lower direct costs, life cycle impacts and indirect external costs than present technologies. It is therefore argued that PV systems are a strategic option for a sustainable future world energy system. Given the present diffusion barriers of PV (i.e. mainly the high direct costs), an appropriate policy framework is needed today, in order to fully exploit this future potential. KiteGen: a revolution in wind energy generation Mario Milanese Dipartimento di Automatica e Informatica, Politecnico di Torino mario.milanese@polito.it Energy has become an urgent, strategic issue at the global scale. At present, about 80% of world electric energy is produced from thermal plants making use of nonrenewable sources (oil, gas, coal, nuclear). The economical, geopolitical and environmental problems related to fossil sources are becoming every day more and more evident. Nuclear plants have their own problems related to security aspects and radioactive waste management. For these reasons it is of primary importance for the scientific community to explore and support new renewable energy technologies, able to provide more efficient solutions than the existing ones to the severe energy shortage of the planet. Wind turbines are currently the largest source of electric power produced with renewable energy (excluding hydro power plants). However, they require heavy towers, foundations and huge blades, which make a significant impact on the environment, require massive investments and long-term amortization periods. All these problems reflect in electric energy production costs that are not yet competitive, in strict economic sense, with the ones of thermal generators. Moreover, wind farms have wide problems of social acceptance due their territory occupation, which is unacceptably higher than for thermal plants of the same power (up to 200-300 times). The lecture illustrates the project KiteGen conducted in collaboration among Politecnico di Torino, Azienda Energetica Metropolitana Torino, Sequoia Automation, Modelway and Cesi for designing and constructing a new class of wind generator, aimed to overcome the above limitations. The key idea is to capture wind energy by means of tethered airfoils (e.g. power kites used for surfing or sailing), whose flight is suitably controlled by pulling the two lines holding the kites. The reasons of the expected dramatic improvements over traditional wind mills are that the energy captured from the wind approximately grows with the cube of wind speed and linearly with the wind intercepted front area. Assuming that the airfoils can fly up to several hundred meters of altitude, KiteGen can take advantage of the fact that as altitude on the ground increases, wind is stronger and more constant Moreover, with lines several hundred meters long, the airfoils can intercept a wind front area much larger than the intercepted area of wind mills, which for structural limits cannot go beyond the size intercepted by 90 m rotor diameters of big 5 MW towers (at present suitable only for off-shore installations). At present, a small-scale prototype is under construction at our department. Numerical simulations performed using an advanced control technique originally developed indicates that it is possible to construct a KiteGen with power up to 1000 MW with a territory occupation much lower than a wind farm of the same power (by a factor up to 50-100) and much lower electric energy production costs (by a factor up to 10-20). Offshore wind parks: a comparative policy analysis for Germany and the UK C. Nunneri1 and A. Kannen2 1 FTZ – Westküste, Christian-Albrechts-University of Kiel, D-25761, Büsum, Germany, e-mail: cnunneri@ecology.unikiel.de 2 FTZ – Westküste, Christian-Albrechts-University of Kiel, D-25761, Büsum, Germany, e-mail: kannen@ftz-west.unikiel.de The need for renewable energies is driven by different issues at global, international (EU) and national scales. Major environmental issues are of global interests, such as the need for reducing CO2 emissions leading to climate change and global warming (Kyoto protocol), the strive towards sustainable use of resources, and minimisation of toxic/dangerous wastes and emissions. At national and international (EU) scale, besides environmental issues, also issues of economic and political nature are behind the recent political engagement for renewables, namely independence of third countries and thereby security of supply and price stability. In this context, the Directive 2001/77/EC of the European Parliament and of the Council on the promotion of electricity produced from renewable energy sources in the internal electricity market (RES-E directive), is one of the keystones of Europe’s renewable energy policy. The EU sees in offshore wind one of the most promising technologies for pushing renewable energy growth. The aim of this paper is to compare the policies and instruments leading to offshore wind park (OWP) construction in the United Kingdom and Germany with respect to their effectiveness. Germany and the UK are often taken as examples of different policies for supporting the development of renewable energy. Many authors have compared the renewable situation in the UK and Germany in particular about the effectiveness of feed-in vs. certificate systems. The efficiency of the German feed-in tariffs has been highlighted in numerous studies and has been successful in promoting onshore wind development. Yet for the offshore wind sector it seems not to work. The actual situation for the Offshore wind sector sees the UK in the leading position, with of 213.80 MW of offshore wind installed capacity around the UK coast, while Germany has currently only ‘big plans’. What are the reasons behind this, and in what aspects does the UK green certificate system offer better conditions for developers? In this paper we seek to analyse what factors have lead to this development. In particular we start from the policy targets and the current achievements and move then to the role of different actors, subsidies, technical and legislative barriers. As both countries are discussing about how to improve their support policies and instruments, such a comparison highlighting pros and cons of the two systems may be a good basis for political discussion. International Overview on Hydrogen and Fuel Cell research Hanns-Joachim Neef Project Management Jülich (PtJ) Research Centre Jülich D 5245 Jülich, Germany E-mail: h.j.neef@fz-juelich.de Increasing environmental problems as a consequence of global climate change and air pollution in congested urban areas, limited fossil resources and the mounting geopolitical dependence on crude oil are enormous challenges for our societies. Fossil and renewable energy sources should be converted and used in a more efficient way. According to energy experts from all over the world, fuel cell and hydrogen energy technologies will play an important role in the portfolio for a future energy economy. This is particularly true for the transport sector which today is marked by an extreme dependency on oil. In addition, fuel cells are a key part of the strategy for a sustainable change of energy systems from central to decentralised energy supply and can be used for portable applications. Hydrogen needs to be produced cost-effectively and with zero or near-zero CO2 emissions. Fuel cells with their high electrical efficiencies and clean exhaust energy conversion have the potential to produce excellent solutions to the ecological and economic problems provided that their development is pursued in a determined way and that their market launch is prepared. The key arguments for the hydrogen and fuel cell technology are: - Hydrogen can be produced from various energy resources and can thus contribute to the diversification of energy supply and ease the dependence on energy imports. - Hydrogen can be used with near-zero emissions at the point of usage. If produced without or with reduced CO2 emissions, hydrogen contributes to mitigate the effects of global warming. Fuel cells are highly efficient in a broad range of applications and can contribute to energy conservation. Cost-effective deployment of hydrogen and fuel cell technologies is foreseeable. Assuming successful R&D efforts, the best estimate is 2010-2015 for stationary applications and 2015-2020 for mobile systems. Early markets for special applications already exist today and will be growing over the next years. Based on experiences and results from intensive R&D and demonstration programmes in the last decades, regional, national, European and international efforts are underway to overcome existing bottlenecks through efforts reaching from fundamental research to market introduction instruments. The problems still to be solved are manifold: cost reduction for all components and systems of a hydrogen economy, performance improvements, manufacturing technologies, infrastructure development, international agreements on codes, standards and regulations, and many more. The International Energy Agency (IEA) and the International Partnership for the Hydrogen Economy (IPHE) together with different international initiatives on codes, standards and regulations are fora in which many countries co-operate to advance hydrogen and fuel cell technologies. At the European level, the Platform for Hydrogen and Fuel Cell Technologies (HFP), relevant programmes of the European Commission and the creation of a European Research Area (ERA) contribute to make Europe a competitive player in hydrogen and fuel cell technologies. Regional and national programmes in many countries all over the globe support researchers from their universities, national laboratories and the industry to advance the technology to make it marketable. The coordination of all these activities is a difficult task in itself and a challenge to regional, national and European programme managers. An agreed upon strategy (or roadmap) and effective communication channels between all those involved in hydrogen and fuel cell technologies are key elements of a successful development. - Transition to Hydrogen Economy: How Soon and How Fast? Frano Barbir Associate Director for Science and Technology UNIDO-ICHET, Istanbul, Turkey barbir@unido-ichet.org Although the transition to a hydrogen economy has undoubtedly already begun, it is still unclear what role hydrogen will play in the future global or regional energy supply. Critiques of hydrogen or hydrogen economy often come from a misunderstanding or misconception of hydrogen’s role. Although hydrogen may be produced from fossil fuels, particularly natural gas, hydrogen as fuel cannot compete in today’s market with the very fuels it is produced from. Hydrogen production from natural gas only makes sense in a transition period to help commercialize hydrogen utilization technologies, such as fuel cells. Full benefits of hydrogen as a clean, versatile and efficient fuel may only be realized if hydrogen is produced from renewable energy sources. While hydrogen from fossil fuels may make sense in a transition period, ultimately hydrogen should be produced from renewable energy sources. Unfortunately, renewable energy sources can hardly compete with fossil fuels, probably even if all the externalities of using the fossil fuels (such as past, present and future environmental damage, political instabilities, including wars) were taken into account. Renewable energy sources typically require a lot of high quality efforts (economic feedback) which makes them more expensive than fossil fuels, which were made by millions of years of free nature work. In some instances it is even questionable whether renewable energy sources contribute any net energy to the main economy. It is for sure that renewable energy sources could have never provided for the economic growth provided by fossil fuels for the last century or so, but they can hopefully lead toward a steady state economy. Utilization of renewable energy sources requires intermediary energy carriers such as electricity and hydrogen. Production of hydrogen from renewable energy sources in most cases involves electricity as an intermediary step. Both hydrogen and electricity are energy carries that together may satisfy all the energy needs of modern civilization. They should not compete with each other, but rather complement each other. With their complementary versatility, they can help in increasing the acceptance and market penetration of renewable energy technologies. However, market penetration of renewable energy sources cannot be left to depend solely on market forces. The benefits of a clean and permanent energy system based on renewable energy sources, and hydrogen and electricity as the energy carriers, are reaching far beyond the horizon of an ordinary customer. The decision on employing renewable energy sources must be a conscious one, made on a national and international level, and based on clear but far reaching benefits to the nation and to the global environment. The Italian research on hydrogen and fuel cells Francesco Di Mario – Angelo Moreno ENEA, TER - IDROCOMB moreno@casaccia.enea.it; dimario@casaccia.enea.it Hydrogen and fuel cells received quite large attention during the last decade, but a growing effort, both in human and economic resources, has been dedicated in Italy to these topics in the last five years. This effort is mainly driven by the following factors: • diversification of primary energy sources, with increase of energy security and reduction of dependence on imported fuels; • reduction of greenhouse gas emissions and local pollution in urban areas; • improvement of industrial competitiveness and creation of new and specialised jobs. Very recently the Italian Hydrogen and Fuel Cell Platform has been launched, strictly connected to the European Platform. An overview on the strategic lines of this platform will be given, high lightening the main objectives planned in the medium term. The presentation will then explain the Italian ongoing projects, carried out in the framework of international, national and regional programs, with participation of research organisations, industries and users. Particulars will be given about the projects that have been recently started at research institutes and industries in the framework of a National R&D Program on “Hydrogen and Fuel Cells” supported by the Ministry of Research and Ministry of Environment through the Special Integrative Fund for Research (FISR). The public funds available for a three year period are about 89 M€ (51 for hydrogen and 38 for fuel cells), for a total cost of the projects of about 120 M€ (FISR funding 70%). ENEA is participating in some of these projects, as well as in European projects carried out in this field; some information about the activities performed in ENEA will be given in conclusion. Hydrogen production from biomass in a two-stage gasifier Paolo De Filippis1, Marianna Zeppieri1, Carlo Borgianni2 Martino Paolucci3, Giovanni Pino3 Università degli Studi di Roma “La Sapienza” Dipartimento di Ingegneria Chimica, dei Materiali, delle Materie Prime e Metallurgia. Via Eudossiana, 18, 00184 Roma, Italy. 2 SEAR sc. c/o Parco Scientifico di Tor Vergata, Via della Ricerca Scientifica, Roma, Italy, c.borgianni@libero.it 3 APAT Via Vitaliano Brancati, Roma, Italy, martino.paolucci@apat.it, pino@apat.it Currently, hydrogen is produced mainly by steam reforming of methane and to a lesser extent from others hydrocarbons. In this scenario, the expected benefits of the use of hydrogen as a fuel, such as an increasing independence from petroleum and the improvement of air quality, are handicapped by the feedstock itself, by the emission of large amounts of carbon dioxide and by the energy required for the process. In order to have a clean alternative to fossil fuels, it is then mandatory to produce hydrogen from non-fossil feedstocks, such as biomass. At present, however, the production cost of hydrogen from biomass is not competitive with those of traditional fuels like gasoline and diesel fuels. A drastic reduction of the hydrogen production costs could be achieved if the gas-cleaning facilities could be eliminated or strongly reduced and if the syngas enthalpy alone were used. Gasification tests carried out in a two-stage bench-scale reactor with a mixture of oxygen and steam as gasification agents indicate that this configuration allows a complete gasification of biomass avoiding the formation of carbon and tar. That is supported also by different two-stage reactors where it is indicated a final tar content without gas cleanup below 25 mg/Nm3. Under this condition, the downstream cleanup facilities could be eliminated or strongly reduced, making such a type of reactor a serious candidate for producing hydrogen from biomass. Moreover, the use of a reforming catalyst proved to be so efficient that the obtained results approach very closely the thermodynamic equilibrium of the water shift and reforming reactions. This enhances the reliability of the prediction based on thermodynamic calculation of the behavior of a two-stage gasifier in the temperature range where the reforming catalyst is effective. This work investigates, by means of a thermodynamic analysis, the yields of hydrogen production when biomass is used as feedstock. In the present study, the biomass selected as potential feedstocks is bagasse and switchgrass. 1 Syngas production by a modified Biomass gasifier and utilisation in a Molten Carbonate Fuel Cell (MCFC) Giovanni Pino, Martino Paolucci, Francesco Geri, Riccardo Marceca (APAT – Via V. Brancati, 48 Rome 00144) pino@apat.it, martino.paolucci@apat.it, riccardo.marceca@apat.it, P. Defilippis, F. Pochetti (Rome “La Sapienza” University – Via Eudossiana, 18 Rome 00100) C. Borgianni (SEAR sc – Rome 00100) c.borgianni@libero.it In order to produce a clean gas for fuel cell by gasification of biomass (enclosed Municipal Solid Waste-MSW) an advanced two-stage gasifier will be utilised and the predictable performance are here analysed. Such a gasifier will be able to provide a syngas almost free of tar (less than 25 mg/Nm3), which will feed a high temperature fuel cell (MCFC). The tar cracker and reformer will be positioned at the inside of gasifier vessel. After gas cooling, filtration (to remove ash content) and depuration (to reduce actual tar content below 1 mg/Nm3), the syngas will feed a MCFC that operates at 600-700°C producing electricity and heat to be utilised in a co-generative system. A typical composition of syngas, for an utilised fixed bed updraft (air blown) gasifier, will be: H2(17%), CO(21%), CO2(13%), CH4(1%), N2(48%). The coming syngas in the fuel cell will undergo a shifting of CO (water gas shift reaction-WGSR), at about 500°C, with consequent enrichment of gas in hydrogen. Reforming of CH4 will provide additional H2 and CO2. Part of CO2 produced, enclosing also that due to the CO shifting and CH4 reforming, and N2 will be utilised also to the start-up and shutdown process of the Fuel Cell. They are not need during normal operation mode. Small amounts of H2 and CO2 are also used to stabilise the chemical process in the hot module of the cell. The final gas mixture, before to react with anode, will be composed of H2, CO2 and N2 only. The high CO2 content is not reducing the cell efficiency in a carbonate electrolyte system. The exhaust gas, at about 400-450°C, will be utilised for a district heating or to produce high-pressure steam and hot water supply. Before flue gas is delivered at the stack, additional heat recovery will be possible. In the flue gas at the stack only part of CO2 and N2 will be present; but coming from a gasification of a renewable resource, residual CO2 and N2 will be sequestered by natural biological cycles and by soil, without contribution to the increase of the greenhouse gas concentration in atmosphere. In this system the global reaction in the fuel cell will provide water steam only. The total efficiency of the system will be of about 60%. A closed cycle will be so realised if only biomass by renewable material will be provided. The Code POLIDEMACO (policy decision making code) for Strategic Choices based Circulation of Benefits. The case of Hydrogen market penetration in the city of Rome P. Boccardelli*, C. Giannantoni§, S. Ulgiati# § LUISS, Roma, Italy ENEA - “Italian Agency for New Technology, Energy and the Environment” Casaccia Research Center - Via Anguillarese Km 1,300 S. Maria di Galeria; 00060 Rome; giannantoni@casaccia.enea.it # * Energy and Environment Research Unit – University of Siena, Italy The Code POLIDEMACO represents the computer form of the evaluation methodology termed as Four-Sector Diagram of Benefits, which is essentially based on: i) the most recent developments of Thermodynamics, in particular those concerning the so-called “Maximum Em-Power Principle” (and its mathematical formulation); ii) the related consequences on Economics (a new concept of Externality); iii) the possibility of adopting evaluation parameters even extremely heterogeneous from each other (exactly because deriving from different theoretical approaches and various scientific disciplines); iv) the proper consideration of the four main “Subjects” (or Sectors) which are usually involved in the global productive process: Firm, Society, the Environment as a Source and the Environment as a Sink; and finally, v) a Decision-Making Process founded more on the estimated external Benefits to be “remunerated” than on possible damages to be internalized. As a case study, the City of Rome is analyzed with reference to the possibility of replacing traditional fuels with Hydrogen, in selected energy supply sectors (namely, transportation and static generation of both electricity and heat for domestic or small firms use). The strategic positioning of selected Hydrogen technologies is evaluated not only with respect to other alternative technologies, but also (and especially) on the basis of the fact that induced Benefits are much higher than Investments required. Special focus is places on an innovative concept of Quality (thus indicated by a capital Q), based on careful insight into Maximum Em-Power Principle features and consequences. This is already generating a profound revision not only in Classical Thermodynamics but also in several related disciplines, and Economics as well. The traditional concept of Externality, for example, can be now reinterpreted as an “excess” in terms of Quality, and thus never ever reducible to the sole action of one subject or the other of the transaction, or to their “sum”. In fact, any generated “excess” of Quality, which emerges from the relationship, is an “extra benefit” which goes far beyond the “generator” and “generating” subjects and contributes to the generation of a higher level of “organization” in the whole system. Improved Performance of Molten Carbonate Fuel Cells due to Innovative Ceramic Materials evaluated by an advanced LCA methodology S. Bargigli1, A. Moreno2, A. Torazza3 and S. Ulgiati4 1,4 Energy and Environment Research Unit, Dept. of Chemistry, Siena University, Italy, bargigli@unisi.it 2 Hydrogen and Fuel Cell Project, ENEA - CR Casaccia, Rome - Italy 3 Ansaldo Fuel Cells S.r.l., Genova - Italy Molten Carbonate Fuel Cell 500 kW power units are currently under development by ENEA and Ansaldo Fuel Cells within research project funded by the European Union and the Italian Government. MCFCs, as a result of the intense efforts in the R&D of innovative ceramic components (anode, cathode and matrix) as well as metallic components, are now characterized by higher corrosion resistance and more constant performance in time. The present analysis provides a special insight on the improvements in the MCFC production processes and the development of innovative materials aimed at extending the fuel cell lifetime. Performance and loading indicators are calculated and compared for several independent improvement options regarding each FC component and over different lifetime scenarios. The evaluation method used for the analysis was developed by our research unit (SUMMA: Sustainability Multimethod Multi-scale Assessment). Stemming from the LCA conceptual framework the method consists of the parallel application of selected impact assessment methods (MFA, Embodied Energy, Emergy, CML) which allows a broader view on the analysed system and helps identify which specific items contribute to a larger extent to the total energy and environmental costs. Keywords: Fuel cells, MCFC, LCA, SUMMA method, Hydrogen, ceramic materials. Evaluation of sugar cane production in Brazil, based on data from producers with good management systems and comparison with published results Jose Tomaz Vieira Pereira1, Jose Antonio Dalbem1 State University of Campinas-SP-Brazil Mechanical Engineering Faculty, Energy Department e-mail: tomaz@unicamp.br The sugar cane agroindustry has experienced a remarkable evolution in productivity. The learning curve reveals noticeable improvements in productivity, both in agricultural and industrial activities. The increase in efficiency in alcohol production in the last 30 years was nearly 50%, due to improvements in agroindustrial processes; the increase was even higher in some specific cases. This paper demonstrates the impact of good management practices in agricultural activities related to sugar cane production, which accounts for approximately 70% of the total costs of sugar and alcohol production. Reliable data are always difficult to achieve, especially in agriculture, which traditionally does not have the same level of data organization as the industrial field. This study was performed by selection of some sugar cane producers with good management systems, for whom detailed data on sugar cane production are available, addressing all production factors. Analysis of these data provides emergetic indices that indicate the evolution both in technology and management. These indices were compared with that previously published ones. 1 The energy metabolism of China and other world countries in relation to the Kyoto protocol and the possible role of biomass and other alternative energy sources. Kozo Mayumi, Jesus Ramos Martin and Mario Giampietro mayumi@ias.tokushima-u.ac.jp, jesusramosmartin@yahoo.es, giampietro@liphe4.org The metabolism of developed countries requires an energy sector capable of delivering a very large amount of energy per capita (quantity), at a huge level of power density (quality), while absorbing only a negligible fraction of: (1) working time (less than 1% of the work force); and (2) colonized land. The structural changes associated with the economic growth of developing countries entail that their energy sector must have the same characteristics expected for the energy sector of developed countries. This is true especially for those countries with a large population and high demographic pressure such as China. Within this background the appraisal of the option biofuels as an alternative to oil is presented as a case study. First, the various typologies of societal metabolism found for different croups of country at the world level are characterized, in order to study the mix determining the total CO2 emissions. Then a scenario analysis referring to the development of China (CO2 emission, energy demand, and implications for the feasibility of Kyoto protocol) is presented in order to characterize the future required performance of its energy sector. Finally, the required characteristics of the energy sector are compared with the expected characteristics of an energy sector based on biofuels. The conclusion is that the high labor and land demand per net unit of biofuel delivered to society makes this option not compatible either with the typical patterns of metabolism associated with developed societies or developing countries willing to undergo a process of fast economic growth. An optimal decision model for energy production from biomasses: a logistics point of view Francesco Fromboa,b, Riccardo Minciardia,b, Michela Robbaa,b, Fulvia Rossoa, Roberto Sacilea,b CIMA, Interuniversity Center for Environmental Monitoring, Via Cadorna 7, 17100 Savona, Italy, francesco.frombo@dist.unige.it b DIST, Department of Communication, Computer and System Sciences, University of Genoa, Genova, Italy One of the key factors on which the sustainable development of our society should be based is the possibility to take advantage of renewable energy. Forest biomass exploitation is one of these possibilities. Wood and in general lignocellulosic biomasses are one of the most common and widespread resources in the world. Their use, in respect of the environment, to produce energy has many advantages such as, for example, the reduction of greenhouse emissions. This paper describes a GIS-based Environmental Decision Support System (EDSS) for an optimal use of forest biomass and untreated industrial wood residues to produce energy. Specifically, the improvements respect to a previous EDSS developed by the same authors (Freppaz et al. (2004); Federici et al. (2005)), are described in detail. The aim of this work is to evaluate the possibility of systematic biomass exploitation for thermic and electric energy production, while achieving a correct management and requalification of the forest and the re-using of the not-treated industrial wood residuals. Attention is focused on the evaluation of different technologies (pyrolysis, gasification, combustion), on energy-kinds produced (heat, electric energy or biodiesel), and on the definition of the harvesting and pretreatment modality (in particular the effects of drying in the efficiency improvement of thermic processes). An accurate model of the forest system is included in the EDSS in order to evaluate the possibility of a sustainable use of the forest biomass and to determine carbon sequestration by forest canopy. A decision model (in terms of decision variables, objectives and constraints), embedding the previously mentioned aspects, is formalized. Finally, a case study is presented and discussion reported. Keywords: Decision Support System, Optimization, Biomass, Renewable Energy a Air versus terrestrial transport modalities: an environmental comparison M.Federici*, F.Ruzzenenti, S.Ulgiati and R.Basosi Department of Chemistry, University of Siena. Via Alcide de Gasperi 2, 53100 Siena. *Corresponding author: federici2@unisi.it, tel 0039 0577 234265 In the last thirteen years, world wide air transportation has shown an average yearly growth rate of 4.6%. Forecasts seem to confirm that this will be the average increase rate for the next 20 years. Within this framework, low-cost airlines are increasing their market share very quickly, making airplane the first challenger of terrestrial transport modalities, not only for medium and long distance, but also for short trips. This is because air transport is obviously faster than trains and cars, and very often it comes out to be the cheaper option in monetary terms, too. Generally airplanes are considered the more energy-intensive and polluting transport modality, followed by high velocity railway. Yet, when air transport is compared to high velocity and more modern terrestrial modalities using a “global scale” approach which takes into account all the energy and materials required to build up infrastructures (i.e. tunnels, railways, highways) and vehicles, the gap among the environmental performances of airplanes, trains and cars seems to significantly narrow. Efficiency and environmental loading have been assessed by means of Material Flow Accounting, Embodied Energy, Exergy and Emergy analyses. Use of JAVA application and XML database for emergy evaluation of agricultural systems Fábio Takahashi, Mileine Zanghetin, Enrique Ortega* Laboratory of Ecological Engineering, School of Food Engineering Unicamp, Caixa Postal 6121, Campinas, São Paulo, Brasil CEP 13083-862 fabiotak@fea.unicamp.br, ortega@fea.unicamp.br Emergy analysis could be broadly used if databases and computer programs were user-friendly and accessible through the Internet. Documents XML (extensible markup language) are being widely used for the storage and exchange of data and XSLT documents (extensible stylesheet language transformation) are being developed for transforming XML documents. In the first stage of development of this type of software, XML archives had been developed to hold the data of agricultural systems of Florida and a XSLT archive was created to transform these data and to allow their reading in browsers. The information of agricultural systems stored in XML files are: amount of each resource used, units of measure, units conversion factors, solar transformities and the emergy flows calculated. The emergy analysis of agricultural systems can be made very easily changing only the amounts of used resources if formularies are standardized. A Java application was developed to allow the users to modify the amounts of resources and products of Florida agriculture systems (available at Internet). This application uses libraries of the Borland JBuilder 2005 system for manipulation of archives XML. In the current stage of development, the program is executed in the user computer. The application was developed for local use and its executable archive is very large (100MB). For this reason, the file download can be difficult for some users. In order to solve this problem, the next step will be the development of an applet that could be executed in a server. This applet will use existing XML documents on the server and a XSLT archive to calculate the new emergy flows, emergy indices and to visualize the results in an Internet navigator. The use of Brazilian agriculture data will be used in the next stage of the research; these systems are more complex than the agricultural systems of Florida so far used. Keywords: emergy analysis, java application, XML. Emergy analysis of frozen concentrated orange juice Consuelo de Lima Fernandez Pereira a and Enrique Ortega b Laboratory of Ecological Engineering (LEIA) School of Food Engineering (FEA) - State University of Campinas Unicamp, CP 6121, Campinas, SP, Brazil. CEP 13083-970 a - clfp@fea.unicamp.br b - Ortega@fea.unicamp.br Emergy Analysis was used to assess the Frozen Concentrated Orange Juice (FCOJ) production chain including the following steps: orchard, FCOJ processing in Brazil, terrestrial and maritime transport (both in Brazil and in Europe), port operations (at Santos and Ghent ports) and orange juice dilution and packaging operation in Europe. Brazil, the major FCOJ world producer, exports about 98% of its production, mainly to Europe (79%). FCOJ production, concentrated at São Paulo State, demands a huge amount of non-renewable energy in its manufacturing and transport. The Brazilian orchards present a very high production per hectare (24 ton/ha.year) as a consequence of intensive use of chemical inputs, specially herbicides and pesticides, labor and energy for irrigation. The orange produced by this system presents a transformity value of 3,44 E 5 seJ/J, renewability of only 28,93%, Emergy Yield Ratio of 1,55, and Emergy Loading Ratio of 2,46. These results alone are important since they show that the agro-chemical model adopted is not sustainable. The results for ready-to-drink orange juice consumed in Europe show an increase in use of non-renewable resources: transformity increases to 7,94 E 5 seJ/J, Renewability decreases to 16,03%, Emergy Yield Ratio decreases to 1,24, and Emergy Loading Ratio increases to 5,24. These findings show that this chain is unsustainable on the long run. These are preliminary results, does not include waste treatment. Energy conservation policy: should public administration give the good example? F.Ruzzenenti*, M.Pagni°, M.Federici*#, C.Bruni°, R.Basosi*#, *Center for Complex Systems Investigation, University of Siena, Italy °Facilities Administration Office, University of Siena, Italy #Department of Chemistry, University of Siena, Italy E-mail: fruzzen@emory.edu, federici2@unisi.it, basosi@unisi.it Two years ago, the University of Siena started a project aimed at reducing both energy costs and energy consumptions. The budget to finance this project came from savings obtained by the University switching from public energy suppliers to private ones after optioning for the electricity free market. This is in accordance with Directive 2002/91/CE, which states that: “The public sector in each Member State should therefore set a good example regarding investments, maintenance and other expenditure for energy-using equipment, energy services and other energy efficiency measures.” This project was intended to implement a policy of environmental awareness and to raise the target of managerial effectiveness of the administration. The Chemistry Department and part of the central administration developed a detailed analysis of energy consumptions and expenditures on the basis of accounting records. Data were then used to produce various indicators to evaluate building performances and to spot out areas of major inefficiency. According to this analysis, besides technical and constructive shortcomings, a large part of the energy losses are caused by user behavior and ineffective management of activities and systems. Preliminary measures, therefore, will tackle the organization of activities and management. Further steps will address the quality and condition of buildings’ bodies, energy appliances and energy supplying systems. Time and Tradition in the Works of Nicholas Georgescu-Roegen Katharine N. Farrell* and Kozo Mayumi# Katharine.Farrell@ufz.de JSPS Fellow, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima City, 770-8502, Japan # Professor of Economics, Faculty of Integrated Arts and Sciences, The University of Tokushima, Tokushima City 7708502, Japan The research follows a strand of enquiry reflected in Mayumi’s recent study of the films of Hayao Miyazaki, which can be understood as part of a wider international academic discourse on the role of symbolism and culture in building and maintaining sustainable societies. The research will study and clarify a relationship between time, production and tradition that is suggested and framed in Nicholas Georgescu-Roegen’s flow/fund model of economic production. It will focus on two writings in which Georgescu-Roegen outlined the details of his flow/fund model and will draw on related works by Professor Mayumi’s. This study is entirely theoretical and focuses on the relationship between (i) the time dependant character of the flow/fund capital category distinctions and (ii) the role of tradition and culture in mediating and regulating economic production. The work is based upon the hypothesis that there is a strong and under-theorised link between the principles at the core of Georgescu-Roegen’s view of capital / nature relationships and his arguments concerning reliance of human societies on exosomatic (outside the body) instruments (including capital and tradition) for the production of economic goods and services. The main task of this research is to tease out the links between these two positions, through a detailed reading of Georgescu-Roegen’s work. We believe that recent developments in the commodity markets, where energy production capacity is now being traded as a commodity, may be explained through insights developed in the course of this study. We propose to describe how changing perceptions of time-frame (i.e. the shortening of time frame associated with the impending oil shock) could influence the resource/capital and/or flow/fund status of energy supplies in the forms of raw materials and conversion/power production capacity. * How far energy efficiency can affect the economic structure: an analysis of long-term, structural, rebound effect, in the road freight transport sector F. Ruzzenenti *§, M. Federici *, S. Ulgiati#, and R. Basosi* * Center for Complex Systems Investigation, University of Siena, Italy # Department of Chemistry, University of Siena, Italy § Corresponding Author: federici2@unisi.it A policy to sustain a more efficient use of energy has frequently been proposed as the main and most successful strategy to reduce energy consumption. This policy was once intended to delay the depletion rate of energy sources, but it is currently employed to address emission reduction standards. Although energy efficiency improvement plays a crucial role in energy conservation policies, it never resulted in an actual reduction of energy consumptions. In this paper, we analyze the shift in the economy that brought about a productive system from a “Fordian”, unilocated, national wide structure to a “post-Fordian”, decentralized, global network-like structure. We then formulate the hypothesis that such a world-wide change was driven, among other causes, by the fuel efficiency improvement that dramatically affected the road transport system in the 20 years running from the early 1970’s. An accurate analysis of truck fuel economy over this period proves that efficiency increased much more than it is commonly believed. In spite of such improvements, global energy consumption of road freight transport system grew more than any other economic sector, mostly due to the increased distance traveled for hauled goods. We argue that this major change in the productive structure offset the benefits in terms of energy conservation brought by a better fuel efficiency of trucks. Furthermore, the general relationship between energy efficiency and the structure of the system seems to represent a recursive developmental pattern that further research must address in order to better understand the impact of efficiency on global energy consumptions. Emergy Based Life Cycle Analysis of Soybean: The agricultural production and industrialization in Brazil Otávio Cavalett and Enrique Ortega Laboratory of Ecological Engineering (LEIA) School of Food Engineering (FEA) State University of Crampinas (UNICAMP) CP 6121, Campinas, SP, Brazil. CEP 13083-970 e-mail: otavio@fea.unicamp.br In this work we evaluated the first stages of the soybean life cycle in Brazil: the agricultural production systems and the industrialization processes by using the emergy methodology as an analysis tool. For the agricultural stage we considered two production models: the model adopted in the South region (“Rolling Pampas”) and the model adopted in the Savannah (“Cerrado”) region. The emergy indicators obtained for the South region soybean production system were: Transformity: 145,000 sej/J; Emergy Yield Ratio: 4.16; Emergy Investment Ratio: 0.32; Environmental Loading Ratio: 0.83; Renewability: 55%; Emergy Exchange Ratio: 4.75. The emergy indicators obtained for the Savannah region soybean production system were: Transformity: 170,000 sej/J; Emergy Yield Ratio: 3.24; Emergy Investment Ratio: 0.45; Environmental Loading Ratio: 0.90; Renewability: 53%; Emergy Exchange Ratio: 5.57. The amount of soybean produced in Brazil in 2004 was 52.2 millions of tons where 54% was processed in Brazil and 38% was exported as grains. We considered (based on the statistical data) that 25% (approximately 4.7 millions of ha) of the soybean was produced adopting the South region production model and the other part, 74% (approximately 13.1 millions of ha) was produced adopting the Savannah region production model. Therefore, the emergy indicators obtained for the soybean in Brazil were: Transformity: 165,000 sej/J; Emergy Yield Ratio: 3.39; Emergy Investment Ratio: 0.42; Environmental Loading Ratio: 0.88; Renewability: 53%; Emergy Exchange Ratio: 5.38. The emergy flows for the soybean production in Brazil in 2004 were: Renewable: 1.03x1023 sej/year; Non renewable: 3.39x1022 sej/year; Feedback: 5.74x1022 sej/year and the Total was 1.95x1023 sej/year. The transport from the farm to the industry using heavy trucks used 1.11x1021 sej/year. The amount of soybean processed in Brazil in 2004 was 28.2 millions of tons. The crashing process used 4.53x1021 sej/year from the economy. The amount of soy oil refined in Brazil in 2004 was 5.1 millions of tons. The soy oil refining process used 7.08x1020 sej/year from economy. From these results it is possible to visualize that the soybean agricultural production system used 94.7% of total emergy involved in the mentioned processes of the soybean life cycle. The transport system used 0.5%, the crashing process used 4.1% and the oil refining used 0.6%. The agricultural production system is clearly the most important system in the initial stages of the soybean life cycle. Because of that, the public policy must be oriented mainly to this stage. The organic production models and other integration processes technologies must be brought forth toward a more sustainable soybean chain. Method to estimate biomass production in natural ecosystems Raúl Benito Siche Jaraa, Feni D.R. Agostinhob, Enrique Ortegab E-mail: ortega@fea.unicamp.br Escuela de Ingeniería Agroindustrial – Facultad de Ciencias Agropecuarias Universidad Nacional de Trujillo, Av. Juan Pablo II s/n. Ciudad Universitaria, Trujillo, Peru. a Laboratório de Engenharia Ecológica e Informática Aplicada – DEA/FEA Universidade Estadual de Campinas, Campinas, SP, Brazil CEP: 13083-970. The calculation of the biomass produced for the diverse types of ecosystems is a very important information for the world-wide commerce of carbon credits (payment for the absorption of the CO2 emissions). The biomass calculation is also important to quantify the recycling of nutrients in order to provide information for regional resources management. Millions of people use the vegetal biomass as direct source of energy, mainly in peripheral countries; therefore the vegetal biomass of a system need to be calculated and considered as a renewable energy supply. Until now, the emergy analysis procedures still does not incorporate this calculation, maybe because the parameter is difficult to quantify. The objective of this work is to elaborate a method to estimate the available biomass energy for several sites around the world, so that it can be used as input in the emergy evaluation. Therefore the method considers the biomass produced in different kind of ecosystems as inputs in the spread sheets calculation. Linear regressions between primary liquid productivity of biomass above of the ground (g/m2.yr) and the evapotranspiration (mm/yr) had been elaborated, besides using data of the world-wide averages of liquid primary carbon productivity (gC/m2.yr). The calculation spreadsheet contains a data base of evapotranspiration values calculated in function of temperature and rain precipitation. The spreadsheet output is the biomass produced in the agricultural unit, as dry mass (g/year) and energy (J/year); values that can be directly used in emergy evaluations. Keywords: biomass calculation, emergy analysis, ecosystems, energy. b Environment and Complexity: Assessing Energy and Material Flows to support the Urban Ecosystem of Rome § M. Ascione§, L. Campanella#, F. Cherubini*, S. Bargigli* and S. Ulgiati* Department of Environmental Sciences, University of Parma, Italy, maascion@libero.it, marco.ascione@yahoo.it * Department of Chemistry, University of Siena, Italy # Department of Chemistry, University of Roma, Italy General goal of the present work was to study stability/sustainability conditions of urban systems related to quantity and quality of available resources as well as to their circulation internally. For this reason we investigated thoroughly: 1) The interactions among urban system and surrounding landscape on local and larger (regional, global) scales; 2) Complexity and complexity increase (organization, number of components, internal dynamics) of the urban system according to increased size and interactions. The following issues have been investigated and are preliminarly discussed in this Workshop presentation: (a) Relation between the quantity and quality of the resources supplied to a urban system and its development trajectory (for example: typology of buildings, urban structure, production and consumption patterns, transport systems, etc); (b) the sustainability of the investigated urban system, by comparing indicators generated from different methods, including emergy. (c) The feasibility and validity of selected proposals aimed at achieving greater sustainability (for example: services of mass transport, increase of renewable energy use, increase of environmentally protected areas, urban waste disposal with energy and raw material recovery, etc). (d) Problems of "carrying capacity“: which fraction of urban assets, population and activity would be sustainable only relying on resources locally available. (e) The environmental consequences of the increased size of urban systems (positive and negative externalities). The investigation was performed by means of a multi-method approach (mass flow accounting, energy analysis, ecological footprint, eMergy synthesis). Results are compared with data for world cities published by other Authors. The usefulness of a multi-method approach in order to clearly understand the domain of application of each method as well as in order to get a more comprehensive picture of the investigated system is also stressed. LCA of waste management options for energy and material resource recovery. The case of Rome F. Cherubini*, S. Bargigli, M. Raugei and S. Ulgiati University of Siena, Department of Chemistry * cherufra@yahoo.it This work investigates the collection and disposal to landfill of the Municipal Solid Waste (MSW) of the city of Rome; several alternative scenarios for waste management are also proposed. The methodological framework of the analysis is the Life Cycle Assessment, that is used to assess the environmental performance of the present situation of Rome and of alternative solid waste management options. Other methodologies used to expand the understanding of the investigated processes within an LCA framework are: Material Flow Accounting (MFA), Embodied Energy and Emergy Analysis. An analytical comparison of the following scenarios is then performed: • Scenario 0: most of MSW are delivered to landfill without any energetic or material recovering; more or less, the actual case of Rome, at present. • Scenario 1: MSW delivered to landfill, but some biogas is recovered and used to produce electricity. • Scenario 2: all MSW are delivered to a sorting plant, where the organic fraction is separated from the rest of the waste (metals are also recovered and sent to recycling); the organic fraction is then processed by means of anaerobic digestion in order to obtain biogas fuel and digestate. The latter is converted to compost. The inorganic fractionis converted to RDF (Refuse Derived Fuel) and burnt to produce electricity. • Scenario 3: the waste is directly incinerated to produce electricity and steam. Results are presented on local and global scales and the limits and merits of each approach are discussed together with the advantage of integrated use. Influence of catalysts structures on steam reforming performances by CFD simulation Nicola Verdone, Paolo de Filippis, Gabriella Compagnone E-mail address: gabriella.compagnone@uniroma1.it (G.Compagnone). Università degli Studi di Roma “La Sapienza” Dipartimento di Ingegneria Chimica, dei Materiali, delle Materie Prime e Metallurgia. Via Eudossiana, 18, 00184 Rome, Italy. Hydrogen consumption is expected to increase sharply in the future due to the environmental benefits of its utilization. However, a real benefit in the use of hydrogen can arise only increasing the efficiency of the production processes. At present, the conventional technology for large scale production of hydrogen is catalytic steam reforming of methane and, to a lesser extent, partial oxidation of higher hydrocarbons. Steam reforming, being based on endothermic reactions, is industrially operated at a high temperature around 800°C over a nickel/alumina-based catalyst. Such a high temperature has major drawbacks including the need for expensive tubular reformers made of special alloys, irreversible carbon formation and large energy consumption. In the last decades a big effort was made in the improvement of both production and separation processes. However, only in the last few years have new catalysts and supports been studied, with the major objective to reduce the wall temperature of the tubular reformer. This objective can be reached improving the catalyst activity and/or the heat transfer in the catalyst bed. A useful tool for the prediction of the behaviour of a fixed-bed catalytic reactor is CFD analysis. This tool allows to quantify the influence of the geometrical characteristics of the bed structures on flow and temperature distributions, and can be used to optimize reactor design to obtain flow and heat transport of maximum uniformity. The aim of this study is to investigate, by means of CFD analysis, the relationship between the local flow field and the wall heat flux in a packed-bed reactor. These aspects are especially critical for highly endothermic or exothermic reactions in low tube-to-particle diameter ratio tubes, such as those used in steam reforming. The main objective is to evaluate the effects of new structured catalytic supports on the steam reforming reactions yields. Simulations were performed under realistic industrial conditions of high temperature, pressure and gas flow rate. Results will be presented showing the actual temperature profiles in the catalyst bed, and the effect on the local heat transfer rates of different conditions at different locations along the catalyst tube. Keywords: hydrogen; steam reforming; CFD; catalytic supports. Photoelectrochemical Water Splitting C. Borgianni1, L. Campanella2, A. Dell’Era3, M. Paolucci4, M. Pasquali3 and G. Visco2 1) 2) 3) 4) SEAR sc. Parco Scientifico e Tecnologico di Tor Vergata - Via della ricerca scientifica, c.borgianni@libero.it Dip. Di Chimica – Università di Roma “La Sapienza” Piazzale Aldo Moro 5 – 00185 Roma Italy Dip. Di ICMMPM – Università di Roma “La Sapienza” Via del Castro Laurenziano 7 – 00161 Roma Italy APAT Via Vitaliano Brancati 48 – 00144 Roma, martino.paolucci@apat.it The aim of our research is to produce hydrogen from water using sunlight as the energy source, with efficiencies high enough to allow commercial production of hydrogen on a large scale. Much research was undertaken in the last three decades to engineer a suitable semiconducting photocatalyst material for water splitting in an electrochemical cell. A good photocatalyst material must have: an energy band gap which is optimum for water splitting (approximately 2 eV with conduction and valence band edges optimally placed with respect to the water redox potentials), strong optical absorption in the visible and ultraviolet spectral regions, good stability in strong electrolytes and efficient charge transfer properties between the semiconductor and the electrolyte. Titanium dioxide is used as a photocatalyst in this research; it is non-toxic, stable and inexpensive. Preliminary tests show hydrogen production. To determine the charge transfer resistance (Rct) of the reaction on the electrode-solution interface, impedance spectroscopy measures in absence and in presence of light were carried out. The Rct decreases from 7310 to 1840 Ohms when the light is turned on. In these preliminary experiments very low yield was obtained, but the use of additives with TiO2, inorganic (e.g. Fe2O3) or organic (anthocyanins) compounds, will supply the desired improvements. Economic growth and environmental quality: an econometric and a decomposition analysis Catia Cialani Department of Economics and Social Sciences, Dalarna University SE-781 88 Borlänge, Sweden E-mail: h05catci@du.se This paper explores the emissions of CO2 in Italy during 1861 to 2002. The Environmental Kuznets Curve (EKC) is applied to explore the relationship between CO2 emission and Gross Domestic Product (GDP) per capita. An Index Decomposition Analysis (IDA) is also applied to investigate changes in emissions between 1990 to 2002. Several factors contribute to change in the emission of CO2. These factors generally include a scale effect, a technological effect and an composition effect. This paper contributes to the existing analyses of the emission of CO2 by analysing which sectors are responsible for the emission and by quantifying the magnitude of the theoretical factors expected to influence the emission. Results indicate the typical inverted “U” form of EKC is not confirmed with our data set for Italy. According our econometric results, there is a positive relationship between economic growth and CO2; following the trend, the maximum emission of CO2 per capita in Italy would be reached when the GDP per capita will be about 26900 US$ (turning point). Basically, two major forces have determined the increase of CO2 pollution in Italy over time: eco-efficiency (pollution per monetary unit of output) and volume effect (volume growth of GDP). Key words: economic growth, CO2, environmental quality, Environmental Kuznets Curve, Decomposition analysis. Energy analysis and emergy synthesis of selected human-dominated ecosystems. A comparative view. a P.P. Franzese, b T. Rydberg, a G.F. Russo and c S. Ulgiati E-mail: pierpaolo.franzese@uniparthenope.it a Department of Environmental Sciences, Parthenope University of Naples, Italy b Department of Urban and Rural Development, Swedish University of Agricultural Sciences, Sweden c Department of Chemistry, University of Siena, Italy In this paper the differences between two methodologies of energy analysis (energy analysis and emergy synthesis) are highlighted and discussed. This is achieved by comparing results from a case study, namely corn (Zea mays) production in Italy, investigated by the Authors, and selected systems from published literature. The two different energy analysis frameworks are: Gross Energy Requirement (Slesser, 1978) and emergy synthesis (Odum, 1996). The case study was aimed at quantifying the contribution of both natural and economic flows to the production processes. Natural and economic flows supporting the investigated system were assessed and calculated as energy equivalent (MJ) and emergy unit (solar emergy Joule, seJ) in order to determine the energy requirement per unit product (MJ kg-1) and its specific emergy (seJ kg-1). Performance indicators are calculated and discussed in relation with results published by other Authors. The theoretical aspects are discussed with reference to spatial and time scale factors and a comparison is also made with other theoretical papers on similar subject (Brown and Herendeen, 1996; Ulgiati, 2001; Sciubba and Ulgiati, 2005). Energy, Sustainability, and Societal Metabolism Joseph A. Tainter Global Institute of Sustainability and School of Human Evolution and Social Change Arizona State University, Tempe, Arizona, USA jtainter@mindspring.com As energy prices continue to rise, we are reminded again that resources are central to societal metabolism and to sustainability. Yet to many citizens of industrial nations societal metabolism is invisible, sustainability is assumed, and energy prices reflect only greed. In the absence of public awareness, sustainability has become the domain of specialists. The disciplinary backgrounds of specialists focus discussions on non-commensurate domains, ensuring that sustainability programs will produce conflict and fail. An alternative approach is to recognize that sustainability is a matter of values, not just resources, and that sustainability goals, conflicts, and costs must be part of analyses of societal metabolism. The experiences and the challenges of the Millennium Ecosystem Assessment (MEA) Monika Zurek FAO, Rome, Italy Monika.Zurek@fao.org Responding to the challenges of integrating economic, social and environmental goals into policy making requires an integrated analysis as well as credible, salient and legitimate information to inform decision-making. The Millennium Ecosystem Assessment (MA) was a four year international work program designed to meet the needs of decision makers and the public for scientific information concerning the consequences of ecosystem change for human wellbeing and options for responding to these changes. The assessment, which involved about 1300 authors from 95 countries, was carried out at the global level as well as thru sub-global assessments and presented its findings in 2005. The main focus of the four MA working groups was on tracking current and future changes in ecosystem services, their driving forces and impacts and how to respond to them. The presentation covers the concepts and main findings of the MA and talks about the process of developing a coherent framework and integrating information across various disciplines and epistemologies. In addition, the presentation discusses how the generated information could help to mainstream environmental goals into on-going economic and developmental decision making processes, as a step towards meeting the sustainability goal in the future. The role of institutions, governance and markets in the pursuit of sustainability Igor Matutinović GfK – Center for Market Research Draškovićeva 54, 10000 Zagreb, Croatia. e-mail: igor.matutinovic@gfk.hr In spite of new warning signs related to deterioration of natural environment (Scheffer at al. 2001; Mooney et al. 2005) and the global warming process (Brook 2005) the belief that free markets and technological progress will be able to cope with these potentially overwhelming treats for humanity is still pervasive. This belief is illusory and misleading for several reasons. Markets in general drive economic process towards those structural changes that are compatible with the expectations of higher returns for shareholders. Resource and energy productivity growth generally happens only as a side effect of profit seeking policies. Markets are blind to species extinction and to loss of biodiversity - what they account for is only that a decline in the number of a species may cause its market price to increase, providing that a species in question has a market value, which is valid for only a tiny fraction of extant biodiversity. Given the enormous difference between characteristic time scales of markets and processes that drive climate change it is very difficult for the former to deal effectively with the treats of the latter. All these intrinsic characteristics of free markets make them unlikely to handle complex environmental and climatic problems that the world faces today. A belief that science and technology alone will eventually solve most if not all of our problems related to societyeconomy-environment interactions is not well supported among the scientific community itself (Ludwig et al, 1993). There is also evidence that required technical innovations do happen thanks to the appropriate constraints placed upon the business sector by the government (Taylor et al. 2003). Therefore, technological progress needs to be steered into a preferred direction and that means that private and government funds should have a consistent common goal if we want to see a desired change happen. Markets, however, do drive change, innovation and productivity in general. Suffice to compare the difference in the dynamics of the Chinese economy before and after the reforms that institutionalized markets, or to compare the dynamics and the rate of innovations in the US and in the ex-Soviet Block economies. Therefore, if we wish to achieve rapid technological change and creative adaptation to new constraints, appropriately steered markets should be kept as one of the key mechanisms. As we cannot rely on markets and technological progress alone - we must look for other mechanisms that may drive the global socioeconomic system towards sustainability. Schafer (1994) points out that possible collapse of global ecosystem is a cultural and not an economic or environmental problem and that solution requires “a fundamental transformation of people’s cultural values, attitudes, practices, and policies which affect the way people relate to each other and the world around them”. According to Robinson (2004), “sustainability is ultimately an issue of human behaviour, and negotiation over preferred futures, under conditions of deep contingency and uncertainty”. The emphasis on values, attitudes, and preferred futures points at the crucial importance of how we perceive the world and our place in it (Matutinović 2006). On the other hand “practices” and “policies” indicate the importance of institutions and governance in the process of achieving sustainability. Building on Salthe’s (1985) hierarchy theory we can analyse the pursuit of sustainability as a process dependent on a certain set of initiating and boundary conditions. The process should bring the world to an extensive reduction of human impact on resources, ecosystems, and climate. It should also contribute to an increase in global equity, poverty reduction, and cessation of violent conflicts. For this to happen, we need to create adequate boundary conditions that would steer collective behaviour into a desired direction. In a hierarchical top-down perspective, the prevailing worldview, which is based on individualism and a bundle of materialist-hedonist values and beliefs, should change in the fist place in order to enable a new direction in the governance process. The process of governance is rendered operative basically, but not exclusively, trough the institutional framework, which directly steers collective behaviour of firms and households in the direction of achieving sustainability. Although there is a visible trend in the increase of global consciousness about environmental and social problems worldwide, the likelihood that a radically new worldview will emerge in a critical mass of human population necessary to drive visible change is very small. Among the major reasons for this: (1) the wide gap in the level of achieved material well-being among major countries of interest and the respective expectations of billions of people to fill it at least partially, (2) the individualist and materialist worldview of the West with its most prominent ideology, neoliberalism, is at its peak of worldwide penetration and socio-political influence. Consequently, we miss an important, high-level constraint to drive the process of socioeconomic change towards sustainability. Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism (MSIASEM) for checking the feasibility and desirability of alternatives to fossil energy. How serious is the addiction to oil of modern societies Mario Giampietro, Kozo Mayumi and Jesus Ramos giampietro@liphe4.org, mayumi@ias.tokushima-u.ac.jp, jesusramosmartin@yahoo.es A metaphor is used to illustrated the key feature of fossil energy which made possible the industrial revolution: the energy sector of a society seen like the heart for the human body. An alternative heart, to be viable, must deliver the supply of blood which is expected by the rest of the body both in terms of quantity and quality. For a developed society, addicted to the quantity and quality of energy supply associated with fossil energy, not everything that can be burned should be considered as a desirable fuel. The methodological approach called Multi-Scale Integrated Analysis of Societal and Ecosystem Metabolism can be used to generate a quantitative analysis useful for checking the feasibility and desirability of scenarios of alternatives to fossil energy. A short introduction, presents the basic rationale and the theoretical building blocks of this approach (Mosaic Effect Across Levels and Impredicative Loop Analysis). Then a few results of previous applications of this method are used to illustrate how MSIASEM can be used for checking the feasibility and desirability of alternative energy sources. This approach can provide a heuristic vision of the “quality” of potential alternatives to fossil energy, due to its ability to contextualize such an analysis in relation to the characteristics of the metabolism of a given society, the characteristics of its energy sector and the characteristics of the metabolism of the ecosystems embedding them. Design of a service-oriented energy system completely based on renewable sources Hans Schnitzer Graz University of Technology Institute for Resource Efficient and Sustainable Systems Inffeldgasse 21b, A-8010 Graz Hans.schnitzer@tugraz.at National energy statistics usually show energy flows. Their presentation includes losses of energy in the various stages of conversion (refinery, power plants, transmission, end-user,…). At the place of the final user, efficiencies of the last energy conversion technology are used (motor, house heating system,…). While “efficiencies” are always dimensionless (useful energy / energy input), the final “energy service” has a completely different dimension (e.g. km t/ litre gasoline). This final conversion can therefore only be described in terms of effectiveness (effect per input) and not by efficiency (output/input). Designing a sustainable energy system based on renewable “solar” resources should therefore not aim at the substitution of fossil resources, but on the provision of the energy-services needed. For a growing use of solar energy the available area often is considered be the limiting factor. For an estimation of areas necessary, energy services can be divided into: • Low temperature (T ≤ 150°C) • Medium and high temperature (T>150°C) • Mobility and transport • Light and information • Power for stationary use More than this, renewables have to replace fossil resources in the production of chemicals and polymers as well. Different paths from solar radiation to energy services show completely different needs for areas regarding quantity (size) and quality. Electricity, biogas, biofuels and hydrogen act as transport and/or storage media. For the Austrian situation, the required areas are calculated. The calculations show, that a service oriented energy system can be completely based on solar energy even in an alpine climate as the Austrian. THE ECO-UNIT: A basis for sustainable development. Analysis of experiences in Latin-America and Europe Enrique Ortega 1, Folke Günther 2, Stephen Hinton 3 Unicamp, Campinas, Sao Paulo, Brazil, ortega@fea.unicamp.br Holon Ecosystem Consultant, Lund, Sweden, folke@holon.se 3 AVBP, Sustainable Development Consultant, Sweden, stephen.hinton@avbp.net 2 1 As the world becomes global, performance indicators show that human systems are unsustainable almost everywhere. Developed economic systems are very similar all over the planet, depending on fossil fuels, unfair payments of human services and rapid extraction of natural resources without concerns for regeneration time. In addition, developed economic systems are displacing local economies and therefore decreasing the organizational diversity of human societies. When oil extraction comes to its peak and energy becomes more expensive, the capacity of the economy to deliver services will decline rapidly. The global human system shows signs of possible collapse in the short term, which calls for innovative, self-organizing processes aimed at preventing such a gloomy picture. Even if the possibility of collapse can be mitigated, the risks of present systems urgently need addressing: ‘Eco-units’ is a new concept of organization of urban and rural development. This type of settlement is under construction in several countries with different approaches. Basically, it is a rural unit that embodies complementary ecological principles and economical objectives by investing in a high degree local self-sufficiency. Main strategies are: [1] simultaneous promotion of ecological maturity and human sustainability by establishing local cycles of nutrients and water: (a) establishing balanced agriculture for local needs using agroecological methods; (b) water purification and recycling, using ecological engineering methods; (c) recovering and preserving ecologically mature ecosystems; [2] establishing local, self-sufficient units to reduce vulnerability for crashes induced by shortage of cheap energy: (a) agriculture for energy purposes (oil, ethanol, biomass) as well as local food and feed production; (b) local production of forestry products for building, energy, nutritional and other purposes; (c) direct capture of incoming solar radiation for heating, drying and other purposes; (d) use of sun derivatives (as local water power, photovoltaics, animal draft) to replace dwindling energy resources from fossil fuels and [3] participation in watershed planning, regional land restructuring, agrarian reforms and Agenda 21 programs. Part of the study discusses methods for the commercial establishment of eco-units using case studies from Sweden and Brazil. Bio-energy production is not the unique concern, size and products depend on ecosystem characteristics. Furthermore, raw material for bio-fuels can be different. However, integrating bio-energy into an economic system of high self-sufficiency to provide a good standard of living with balanced ecology is key. The study compares and discusses experience from several countries. Future development of the electricity systems with Distributed Generation Angel Antonio Bayod Rújula Universidad de Zaragoza, Spain aabayod@unizar.es Electrical power systems have been traditionally designed taking energy from high voltage levels, and distributing it to lower voltage level networks. There are large generation units connected to transmission networks. In these networks there is a bulk transport of electricity, with central coordination of the control (modulating outputs of generators). Demand is passive and uncontrollable, connected to Distribution networks (EHV, HV or LV). Distribution systems are also passive and, in the lower levels of voltage, radial in operation. They are designed to accept bulk power form transmission system and distribute to customers, generally with unidirectional flows, although some are interconnected. Load demand is continuously growing and there is a need to respond to climate change challenge (develop sustainable electricity systems), without forgetting the need to maintain competitiveness, and the need to enhance the security of supply. Distributed generation is defined as generation located in or close to the demand places. Electricity is produced by using small power technologies. They are small, modular systems that can be combined with management and storage energy systems in order to improve the operation of the distribution system. From an environmental point of view, distributed generation is considered clean, reliable and secure. Within this definition are included: - Autoproduction units (including cogeneration and the ones using residual energies). - Facilities using non-consumable renewable energies (biomass and biofuels). Within this group a sub-classification is defined according to the renewable energy that is used: solar energy, wind energy, geothermal energy and wave energy, hydroelectricity. - Facilities that use nonrenewable waste energy sources (solid urban waste or others). - Facilities of treatment and reduction of the residues of agriculture, farming and other services (treatment and reduction of pig dung, mud and other residues). The expected benefits of Distributed Energy Sources are: generation buses and consumption are closer, reduction of the transmission and distribution losses, promotion of renewable energies, increased network asset utilisation, deferring of investments in lines and classical power stations, enhanced reliability and security, etc. In the future there will be a large number of small generators connected to the distribution networks. If efficient planning and an optimum operation of the grids to which the generation plants are connected are achieved, it will be possible for DGs to play a greater role in the future, contributing to the improvement of the energy efficiency and to a reduction in the distribution cost and also to an improvement in the power quality. But distributed generation can also give some technical problems: embedded generation can cause an inversion in the energy flow, i.e. energy is sent to the high voltage level. This fact can affect the quality and stability of the network and requires a change in the operation and protection of the system. In other cases, the quality and stability of the network can be affected. When distributed electricity supply of Renewable energies and CHP (combined heat and power) surpasses a particular level this may require adaptation to the planning and operational management of the electricity network infrastructure, changes in the organisation of system services and modifications of technical standards and authorisation procedures. Article 14/7 of the EU Directive says: “When planning the development of the distribution network, energy efficiency/demand-side management measures and/or distributed generation that might supplant the need to upgrade or replace electricity capacity shall be considered by the distribution system operator”. Efficient integration of a rising share of DG requires network innovations (in areas of system design/topology and system operation and control, including storage). A development of active distribution network management, from centralised to more distributed system management is needed. Information, communication, control infrastructures will be needed with increase complexity of system management. In future developments, this distributed generation will be connected to active distribution networks (EHV, HV and LV), and the total control will be coordinated. This integration will enhance the value of DG and Demand Side Management. Generation and grid constitute one system. Some innovative concepts as Virtual Power Plants and MicroGrids will be presented in the final paper. Thermodynamic optimization in industrial and practical systems Stanislaw Sieniutycz Electronic address: sieniutycz@ichip.pw.edu.pl; http://www. ichip.pw.edu.pl Faculty of Chemical and Process Engineering Warsaw University of Technology PL 00-645, 1 Waryńskiego Street, Warsaw, Poland We present a thermodynamic approach to simulation and modeling of nonlinear energy converters, in particular radiation engines. Basic thermodynamic principles lead to expressions for the converter’s efficiency and limiting generated work in terms of the entropy production. The real work is a cumulative effect obtained in a system of a resource fluid, a sequence of engines, and an infinite bath. Nonlinear modeling involves methods of dynamic optimization such as maximum principles, variational calculus and dynamic programming. The primary result of the optimal modeling is a finite-rate generalization of the classical, reversible work potential (exergy). The generalized work function depends on thermal coordinates and a dissipation index, h, in fact the Hamiltonian of the optimization problem of minimum entropy production. The generalized work function implies stronger bounds on work delivered or supplied than the reversible work potential. Role of the thermodynamic reasoning, nonlinear analyses and dynamic optimization (variational methods) is underlined. As an example of the kinetic work limit in a nonlinear system, generalized exergy of radiation fluid is estimated in terms of finite rates, quantified by Hamiltonian h. Keywords: thermal efficiency, thermal machines, entropy production, radiation engines CO2-Capture with liquid and fixed Amine-Solvents K. Brechtel, H. Thorwarth, G. Scheffknecht Institute of Process Engineering and Power Plant Technology (IVD) Pfaffenwaldring 23, 70569 Stuttgart, Germany Phone: +49 (0)711/685 63487 Fax: +49 (0)711/685 63491 e-mail: brechtel@ivd.uni-stuttgart.de Today it is known that one major reason for global warming is the anthropogenic emission of greenhouse gases (especially CO2). With the ratification of the Kyoto-Protocol the European Union, and especially Germany, assured a reduction of greenhouse gases. One of these dangerous gases for the atmosphere is CO2, which is emitted in considerable amounts from power stations. For lowering the CO2 Emissions and in consideration of the greenhouse effect, the European Union promotes the research in CO2-Capture and Storage. For this, several projects for pre- and post-combustion capture and also in new technologies are running all over Europe. The best developed technology at the moment is CO2-capture using amine scrubbers. The major disadvantage of this technology is the reduction of the power plant energy efficiency up to 13%-points, caused by the consumption of steam for amine regeneration. To reduce the required regeneration energy new amines or new mixtures of amines (e.g. primary and tertiary amine) are developed. The advantage of primary amines is the fast reaction with CO2, the disadvantage is the high energy need for regeneration. Tertiary amines need less energy for regeneration, but react very slow with CO2. This is why tertiary amines are activated by adding primary amines. But the disadvantage of liquid amine-mixtures is the higher regeneration energy consumption, caused by the primary amine. To avoid this it is possible to use mixtures of fixed primary and tertiary amines. Therefore experiments with ion exchanger (fixed primary amine) have been carried out at IVD. These tests show that it is possible to capture CO2 from gas phase by the use of an ion exchanger and that it is possible to regenerate the exchanger with tertiary amines. With these results a new capture process will be developed at IVD. The major advantage of this process will be the possibility to separate the two used amines (primary and tertiary) for the absorption and desorption process. With this the advantage of the primary amine can be used at absorption (fast reaction) and the advantage of the tertiary amine at desorption (low energy demand for regeneration). The presentation will include some general information about CO2-capture with aminescrubbers e.g. used solvents, energy requirement and influence on power plants. The second part of the presentation will show results from experiments using ion-exchanger, carried out in laboratory tests. Identification of Environmental Burden linked with Carbon Capture and Storage O. Mayer-Spohn, M. Blesl, U. Fahl, A. Voß University of Stuttgart, Germany OM@ier.uni-stuttgart.de The scientific discussion on Carbon Capture and Storage (CCS) is characterised mainly by issues of technical feasibility, cost and risk evaluation, but scarcely by environmental considerations. Because CCS constitutes a contribution to climate protection, it is primarily regarded as entirely positive measure for the environment. However the mitigation of green house gases by capturing CO2 from power plant emissions comes along with additional emissions and resource use from facilities for carbon capture and transportation. How significant is this additional environmental burden of CCS compared to the benefit of captured CO2? Does CCS still constitute an overall benefit for climate and environment or does it promote climate protection at price of considerable other environmental burden and thus shift problems? This presentation shows how the approach of Life Cycle Assessment is used to investigate and evaluate the environmental performance of CCS and to highlight the dimension of linked environmental burdens. Exemplarily one CCS path, pre-combustion CO2 capture in an IGCC power plant and following CO2 transportation until the point of storage in an underground formation is investigated. Sensitivity analyses including a comparison of different means of transportation (pipeline, ship, lorry, train) show the dimension and relevance of environmental burden along the CCS chain. All results are shown in contrast to electricity generation in an IGCC power plant without CO2 capture. Financial mechanisms for heat sector projects in Latvia Peteris Shipkovs, Galina Kashkarova, Kristina Lebedeva Energy Resources Laboratory, Institute of Physical Energetics E-mail: shipkovs@edi.lv The paper presents Boiler house and District Heating System Reconstruction Project realization and financial options that was used in this project. In Latvia approximately 70% of the heat supply is provided by municipal DH systems and about 60% of the dwellings are connected to these systems. Due to the relatively large forest areas and close-by supply of wood, conversion from oil to wood has taken place over the last decade. In 2004 20% of the energy used for heat production are based on wood, 69% on natural gas and 8% on heavy fuel. There are approx. 3,000 boiler houses and up to 1,500 boiler houses used biomass. In many cases these boiler houses are of small scale with low efficiency. Several financing mechanisms are used in Latvia for heat sector projects. The most important are as follows: 1. Commercial loans – usually municipalities guarantee for the loan by the municipal budget. 2. Involvement of a private investor using take-or-take contract for the produced heat (Ludza Boiler house and District Heating System Reconstruction Project). 3. State support scheme – partly grant from the state budget through the state investment program. 4. European structural funds, for the heat sector The European Regional Development Fund (ERDF) is relevant. 5. Other donor financing and bundling of small projects (United Nations Development Program, UNDP and Latvian Environmental Investment Fund, LEIF). Ludza is a city with 6,000 citizens located in the eastern part of Latvia. Involvement of a private investor using take-or-take contract for the produced heat was successfully Ludza Boiler house and District Heating System Reconstruction Project. The project involved conversion of the boiler house from heavy fuel oil to wood chips and diesel for peak load. The Dutch company ESSENT Baltic invested in the reconstruction of the boiler house. ESSENS Baltic entered a take-or-pay contract with the municipality. The municipal was responsible for the payment in this Project and had to collect payments from the consumers. The most important results of the Ludza project are presented in the paper such as: it is an advantage that the municipality does not have to take loan for financing of the plant because loans with municipality guarantee are limited; 5,000 inhabitants receive environmentally friendly heating services; CO2 emissions are reduced by 80%, saving 11,200 tons, etc. Energy Rebound and Economic Growth Reinhard Madlener1 and Blake Alcott2 1 Centre for Energy Policy and Economics (CEPE), ETH Zurich, 8032 Zurich, Switzerland. Corresponding author. Tel. +41 44 632 06 52, Fax. +41 44 632 1050, Email. rmadlener@ethz.ch 2 Department of Land Economy, University of Cambridge, Cambridge CB2 1QA, U.K. The more efficient use of energy, ceteris paribus, is postulated to lead to greater, not lower, consumption of energy. Building on the work of Jevons (1865), Khazzoom (1980), Brookes (1978, 1990, 2000, 2004) and Saunders (1992, 2000), a production function is offered modelling technological energy efficiency increases, input as well as output prices, consumer behaviour with elastic price/demand reactions, marginal consumers, and new outputs previously uneconomical at the lower level of technological efficiency level. The theory that rebound is greater than unity predicts the observed real-world correlation between rising consumption and rising efficiency of energy use, however difficult it may be to define a precise metric for the latter. The opposing theory, that rebound is less than unity and that efficiency increases therefore cause less consumption than before, requires on the other hand extremely strong factors that do account for observed economic growth. The paper’s hypothesis is shown to be supported by neo-classical economics’ demonstration, going back to Solow (1956, 1957) that labour and capital as absolute magnitudes account for only a small proportion of economic growth. It is suggested that matter or natural resources, seen as mass/energy by Ayres (1978), among others, is indispensable to production functions. Keywords: energy efficiency, economic scale, rebound, backfire. Energy efficiency targets using tradable certificates. Microeconomic aspects and lessons from Italy Franco Becchis franco.becchis@fondazioneambiente.org Fondazione per l’Ambiente www.fondazioneambiente.org Contexts Demand side management (DSM) and energy efficiency (EE) policies have a primary role in the main scheme of European strategies for the environment, as stated in the new proposal by the European Commission for a Directive on the promotion of end-use efficiency and energy services (December 2005). The role of DSM and EE policies is considered particularly relevant for the actual implementation of the Kyoto Protocol and for the general reduction of the impact on scarce natural resources. To achieve sound environmental objectives governments can use many different instruments, ranging from standard to subsidisation/taxation approaches. In the EE field Italy has decided to accompany traditional policy instruments with an innovative one based on tradable certificates that came fully into force in January 2005 with two national decrees (Ministry of Industry, July 2004) and a few specific regulatory acts from the Italian Regulatory Authority for Electricity and Gas (December 2004). The innovative policy is based on the institution of a market of EE certificates, the so-called “White Certificates” (WhC). WhC potentially represents, with respect to standard instruments, a better incentive to start EE projects. They are based, through of a fairly articulated system, on the transfer of financial resources from obliged subjects (the large distributors, probably characterized by relatively high marginal costs for each unit of saved energy) to non-obliged subjects (who may be favoured by better micro-economic conditions to attain marginal energy savings). This principle may also lead to the minimization of the overall social cost. Outline of the presentation The paper deals with three main issues: 1- the microeconomic aspects of energy saving and energy efficiency, the working of ideal markets and the relevant market failures; 2- the effect of corrective policies like the Italian scheme (obliged subjects plus tradable certificates) 3- the problems in the enforcement phase and an experience of policy-accompanying in Regione Piemonte by Fondazione per l’Ambiente, aimed to ease EE projects and WhC market at regional level International comparisons are shortly given in order to envisage the international context. The exosomatic evolution of human kind, power and the importance of bioeconomics Claudio Cattaneo Can Masdeu, Antic Camí de St.Llatzer s/n, 08042 Barcelona ICTA – UAB Barcelona Phone: ++39 686906791; e-mail: claudio.cattaneo@liuc.it Lotka’s ideas of the exsomatic evolution of human kind was interpreted by Georgescu-Roegen with reference to the rise of social conflict, the distribution of political power, access to natural resources and to decision making power. Also, in physical terms, it implies the questioning of the supposed 4th law of thermodynamics according to which material recycling is not possible. Georgescu-Roegen conceived the actual economic process based on industrial and on artificial exosomatic processes. Tsuchida and Murota conceived the feasibility of material recycling under “well preserved water and soil” [Tsuchida and Murota, 1985]. In fact all biological processes recycle matter efficiently, in a self-organized way. In this paper I conceive the importance of an economic process based on living and self-organized processes. This is considered a matter of bioeconomics. Keywords: exosomatic evolution, endosomatic energy, bioeconomics, permaculture Natural environment and economic growth: looking for the energy-EKC Tommaso Luzzati e Marco Orsini tluzzati@ec.unipi.it, m.orsini@ec.unipi.it Most of the debate on the Environmental Kuznets Curve has focused on pollutants like suspended particulate matter, SO2, NOx, CO2. In this paper, we will focus on energy (primary energy use). Energy is not taken as “the indicator” of either human pressure or impact on nature. No single indicator can meaningfully represent a set of so greatly heterogeneous effects. Energy is chosen firstly since it allows avoiding the tricky issue of substitution of old with new pollutants. Secondly, and more importantly, the influence of energy use is pervasive, not limited to direct effects. Actually, energy makes it possible to extract and move huge amounts of matter; huge material throughput is at the root of the current environmental degradation. A brief look at the narratives and models for the EKC helps us to set a framework where primary energy use (total rather than per capita) is compared with per capita GDP. We focus on the period 1971-2003 by using both aggregate data for the world and a cross-national (113 countries) time series panel of data. Our investigation of the energy EKC firstly treats world as a unique country (so to neutralise trade effects). We move then at country level. After a brief description of the main trends and patterns, we test the energy-EKC hypothesis with non-parametric regressions and traditional panel data analysis with different model specifications. Our results are as follows. For the world as a whole, the relationship looks positive and linear. After 1989, data suggest a lower (but still positive) slope. At disaggregated level, patterns are very different among countries. In most cases, they can be approximated by a positive linear relationship, with very heterogeneous slopes and intercepts. Only some “oil producers” and poor countries that experienced wars show negative slopes. If any regularity is to be found, one can say that in “rich” countries the heterogeneity of patterns is lower than in poor countries. The same applies for the elasticity of energy to GDPpc. In conclusion, data do not support the hypothesis of an energy-EKC. Keywords: Environmental Kuznets Curve, Energy, non parametric estimates Peak Oil: Where do we stand in 2006? Ugo Bardi ugo.bardi@unifi.it Many claims and misinterpretations have accumulated around the concept of "peak oil", a subject that becomes less understood as it becomes more popular. This communication tries to provide an assessment of the situation with oil and other fossil fuels production as it stands in 2006. In general, the production of mineral resources can be interpreted according to dynamic socio-economical models which use the geological data as an input, or derive it from data fitting. Several models have been developed and tested, the earliest ones where the empirical one proposed already in the1950s by Marion King Hubbert, followed by the studies performed in the 1960's by Jay Forrester at MIT and explored in detail in the famous study "The Limits to Growth" of 1972. From that time, models have been refined and improved. There is a general agreement that the production of a mineral resource tends to peak and starts to decline well before its complete physical depletion. Most analysts place the peak for oil within the first decade of 21st century, although some see it taking place at a later time. Oil is not the only resource about to peak, other fossil resources such as gas, coal and uranium all are at various stages of their depletion curve. Little is known about the consequences on society and economy of the peaking of major energetic resources, but also in this field dynamic models may provide some insight. The transition from fossil to solar energy Luigi Sertorio University of Torino, Italy sertorio@to.infn.it The energy needs do not follow from axioms of the economic laws, are not a "dictum" of science, or a necessity of technology. First of all the energy needs are extremely uneven (orders of magnitude) from one nation to another, from a social group to another. The consequences of such inequalities are not in the direction of human progress but rather in the retrograde pathway. We may understand the present scenario of the fossil energy consumption in the frame of history and in particular history of the technological opportunities. In tact the rapid growth of such opportunities has molded the fabric of societies in abrupt ways. The phenomenological result is a fragile body with poor inner structure, mainly constituted by few producers and many consumers. The millenary tradition of acquisition of tools, resources, and the relatively slow adaptation of society moving from an equilibrium state to the next has been violated: the consumer's society has negligible feedbacks, therefore is unstable. Injecting additional energy can only make the collapse worse. At the present time the control of the energy sources (any kind of source) is intolerably violent, and is the indication of a shortage of thought rather than a shortage of energy. Science, philosophy, have been left behind, almost non existent within the cheap logic of growth. This talk is a little step in the direction of scientific knowledge. The future challenges for “clean coal technologies”. Joining efficiency increase and pollutant emission control Alessandro Franco, Ana R. Diaz, Dipartimento d’Energetica “L. Poggi”, Università di Pisa Via Diotisalvi 2, 56126 PISA – ITALY franco@ing.unipi.it, ana.diaz@ing.unipi.it The growing energy demand of the developing countries coupled with the need in significant reduction in greenhouse gases emission (GHG) are the challenging tasks of future energy policies. Indeed, nowadays, the energy problems are based on the fact that no combination of carbon-free energies is currently capable of replacing fossil fuels at the main source of the world’s primary energy requirements. So far the perspectives for the expansion of carbon-free energies are not realistic due to technological and resources limitation. Certainly, while new renewable technologies are confined by their intensive land used and water requirements, coal represents at the present about 70% of the world’s proven fossil fuel resources and still provides about a 30% of the world’s electricity. Moreover, coal is also the more delocalized resource and it has the lower cost among the different fossil fuels. Thus, it is a matter of fact that coal is likely to remain one of the main sources of primary energy for a long time and it will play a strategic role in the medium- long- term energy production systems. Electric power from coal has been predominantly generated in pulverized coal-fired power plants, where hot products of coal combustion exchange heat with steam in a boiler in order to produce work in a steam turbine. Due to thermodynamic (mainly the use of water) and metallurgic constraints, the efficiency of such plants is rather low. Modern coal-fired power plants obtain an efficiency of about 38- 40% (based on the Lower Heating Value of the fuel, LHV) operating at 250-300 bar and at maximum temperature of 530-560 °C. But also they are characterized by rather high carbon dioxide emissions (about 800 g/KWh of electric energy produced). Higher efficiencies can be achieved by further increasing steam parameters; for example for supercritical boilers operating at pressures around 350 bar and temperatures of 700 °C efficiency is expected to be around 47% (LHV). Nevertheless, the crucial question about the future of coal technologies remains the perspective of a considerable reduction of the CO2 emissions. The aim is the possibility of reaching the CO2 emission levels of the Natural gas combined cycle plants whose emissions laying around 350-400 g/kWh. To overcome these barriers it is necessary to develop a new generation of advanced coal conversion technologies, known today as “clean coal technologies” which provide an effective conversion of coal into electricity by employing the gas turbine cycle. The most promising are the Integrated Coal Gasification Combined Cycle (IGCC) and the Externally-Fired Combined Cycle (EFCC) power plants. The development of those technologies would match a good efficiency increase with an adequate control technology for CO2 emissions. Furthermore, The IGCC and the Pressurized bed combustion (PFBC) represent the state-of-the-art technology and provide electric power with an efficiency of about 41-46% LHV efficiency. However, they have a high level of complexity and higher equipment and maintenance costs, resulting in severe economic penalties. The EFCC, being a very promising technology, also needs further technical developments in its high temperature heat exchanger for Gas combustion-Air. The perspectives for a correct use of coal as energy source are based on the success into the energy market of “clean coal technologies”, where good thermodynamic performance of the power plant are joined with a control of pollutant emissions (mainly CO2 emissions). This is an objective not easy to be reached for different reasons. On the one hand coal is not a uniform source due to its extremely variable composition; this made difficult to reach a standardization of advanced technologies that can be very sensitive to the different compositions. On the other hand the coal combustion produces structurally more pollutants that the other fossil fuel since it contains mainly carbon as reactive component (turning to CO2) and sulphur (turning to SOX) but very few hydrogen (turning to H2O). From the aforesaid considerations, the aim of the work in object is to discuss about the perspectives of the particular field of clean coal technologies starting from an exhaustive analysis of them, from the point of view of thermodynamic efficiency and emission control and of their connection. In particular three main strategies will be discussed and analyzed in order to mitigate the CO2 emissions produced by coal technologies. The first strategy is the control of CO2 emissions from existing coal fired power plants through end-of-the-pipe separation processes. The most suitable technology appears to be the chemical absorption technology, which is based on the CO2 concentration and its partial pressure at the capture point. This method has been widely analyzed in literature, been the most applied one. Under an energetic point of view this technology requires an great among of energy to achieve the CO2 capture, transport and storage, having a great impact on the thermodynamic performance of the plant that seriously decrease power generation efficiency. Economically talking, the development of this technology without much modification to the plants can be a transitory “inexpensive” short-term solution for existing plants. The second strategy is guided by the need of more integrated capture technologies into the thermodynamic of the system and therefore less energy intensive. The use of new conversions technologies where the carbon can be removed at a convenient stage of the process includes advanced coal power plants as the above mentioned IGCC. In these integrated technologies the capture can take place before the combustion, with a fuel gas under high pressure and temperature conditions, therefore the capture devices are smaller and accordingly less costly. Furthermore, the capture energy required in integrated technologies can be taken from possible marginal losses of the plant. Also oxy-fuel closed or semi-closed technologies are been proposed, the principle O2/CO2 is based on the oxygen production (95% purity or higher) for the combustion instead of air where the working fluid is basically CO2, and the exhaust gases are a very concentrated stream of CO2 and H2O. Under these conditions CO2 can be sequestrated “more easily” since it is not in mixture with other gases usually present in the combustion. The most suitable separation technology must be selected based on the type of process and the operation conditions where the CO2 is removed. Apart from the well-known separation technologies like physical, chemical absorption/adsorption, different new capture technologies are under study, such as membranes separation (requiring further development and testing) or cryogenic separation (a very energy-intensive technology). The third option is represented by the direct decarbonisation of the fuel; this includes technologies where the carbon is removed to produce hydrogen that can be used in advanced gas turbine plants derived from Steam Turbine Injected Gas technology. At present this strategy seems to be the less convenient one, but some further investigations are necessary. Fuelling the Future: Options for Australia’s Transition to a Low Carbon Economy Barney Foran* and David Crane§ * Centre for Resource and Environmental Studies, Australian National University, Canberra, Australia. foran@cres.anu.edu.au § SunWheel Technologies Limited, Minchinhampton, United Kingdom, http://www.sunwheeltech.org.uk/ This study tests Australia’s transition from a fossil fuelled economic system to one based on woody biomass, and in particular one where bio-alcohols and bio-oils replace petrol and diesel. It seeks to concurrently resolve the looming policy dilemmas of transport fuel security, greenhouse emissions, landscape degradation, trade balances and regional renewal by re-clothing substantial portions of Australia’s farmed lands with wood crops that underpin a carbon neutral transport fuels cycle. The current debate on ‘ethanol from sugar and grain’ is a small part of the transition tested but is articulated (ie the current debate) with such a marginal perspective, that it may not have much effect on either fuel security or greenhouse emissions. This study finds that it is feasible to underpin a substantial proportion of Australia’s transport fuel cycle with a wood feedstock planted on 25 to 50 million hectares of Australia’s tamed lands. It may be possible to do this and maintain most agricultural production around the current level by increasing the intensity of production. However the transition may be less risky if agricultural production is lessened commensurate with product quality increases that maintain financial yields. It is possible to maintain rates of national economic productivity and give large decreases in greenhouse gas emissions, while undergoing the transition to a transport fuel cycle with a lower greenhouse intensity. The core technological concept behind a successful transition rests on concepts such the ‘biomass cascade’ and ‘energyplexes’. The former underpins a future world where many industrial and fuel feedstocks are supplied by crops, trees and even algae. The latter includes concepts such as ‘distributed energy systems’ and in this case is focused on regional energy factories producing liquid fuels, electricity and a range of by-products. A growing Australian economy with fuel self sufficiency would eventually require many hundreds of these ‘energy-plexes’ and bring to regional Australia the development stimulus required for its re-invigoration. It should be noted that the transformation processes behind these energy-plexes could also be fuelled by black and brown coal backed up by geo-sequestration of carbon dioxide. This study can contribute towards the discussion of whether a biomass-based or a fossil-based economy is preferable, but it does not make that decision. The study also tests the feasibility of several different pathways and technologies towards a renewable electricity system. It finds that many of these are feasible even if their capital cost is two to three times today’s levels to provide storage and management systems which buffer variability. A similar outcome has been found for several renewable technologies especially windpower in a continental scale study undertaken for the CSIRO Energy Transformed program. However in the current state of enumeration, these transitions can decrease rates of economic productivity for two decades while the fossil fuelled infrastructure is being replaced. There are many partial solutions to a successful energy economy in 2050 and selections of these have been grouped into ‘blue’, ‘green’ and ‘technicolour’ scenarios which attack the problem respectively from a ‘mostly technical’, ‘mostly environmental’ or ‘use what works’ perspective. Each scenario is imminently feasible within the confines of the analytical approach used, but each brings with it a particular set of uncertainties which could reduce the scenario’s effectiveness e.g. the risk of carbon dioxide venting from sequestered storages in the ‘blue’ scenario, or a drought driven lower biomass productivity in the ‘green’ scenario. Many caveats must be applied to the outcomes of the study and in particular, its scale and its modelling methodology. The scale of the study is national and the technologies tested seek to change national outcomes over the next five decades and possibly will not make sense in a sector by sector sense over short timeframes. At a landscape scale, developing a large biomass resource will affect regional hydrology and therefore water runoff. This study suggests the effect is small if marginal arable lands are developed first, but small scale catchment modelling must be undertaken to give robust analyses of this. The modelling methodology is based on the physical numeriare of embodied energy as the prime determinant of national function, rather than economic concepts of productivity. Thus the feasibility of key study outcomes must be tested within appropriate social and financial analytical frameworks before they are seen as robust in an industry or a policy sense. Current Situation and Perspectives of Polygeneration Systems a Weidou Nia , Lingmei Wanga,b, Zheng Lia Department of Thermal Engineering, Tsinghua University, Beijing 100084, P. R. China b College of Engineering, Shanxi University, Taiyuan 030013, P. R. China E-mail: wanglingmei@mail.tsinghua.edu.cn Polygeneration considered from the point of view of comprehensive optimization, is a highly flexible and cross-sector integrated system of resources, energy and environment. Using coal, petrocoke or heavy oil residues with high sulfur content as feedstock, syngas (the main components being CO and H2) is produced through oxygen-blown gasification. Syngas has several uses. Polygeneration could increase the adaptability and robustness of energy-service companies in the marketplace, providing them with flexibility in meeting demands in different market segments while achieving lower production costs and reducing the risks of reliance on a single feedstock. In addition, with the possibility of achieving high conversion efficiencies and low polluting emissions and facilitating carbon capture, they could deliver high-quality energy services in a cost-effective way while meeting stringent environmental requirements. The current situation of polygeneration systems is analyzed with special focus on energy flows, integration mechanisms, , performance, status of key technology of polygeneration in China, etc. At the end, based on international and national development, a perspective of polygeneration system that includes theory, key technology and policy is presented. As a case study, fuel (methanol) and electricity production in a polygeneration system is analyzed by means of energy, exergy, thermoeconomic, and emergy analysis, integrated with Life Cycle Assessment, Life Cycle Cost, and industrial ecology considerations. The relevance of polygeneration to environmental protection and better use of resources is discussed. Framing CO2 in the European Car Sector. Simulation of Technology and Regulation Driven Scenarios Massimo Chindemi Eni S.p.A., Via F. Maritano, 26, 20097 San Donato Milanese (Milano) Italy E-mail: massimo.chindemi@eni.it Oil products dominate energy use in the mobility sector which is responsible for a significant share of overall CO2 emissions. In Europe, 737 Mt (26% of 2789 Mt of CO2 produced by anthropogenic activities in 2003) derive from transports: 93%, i.e. 682 Mt, are ascribed to the road mode. Due to the stoichiometric relation between CO2 emissions and the fuel that is burnt in the engine’s combustion chambers, CO2 emissions from road transport reflect the number of vehicles, driver behaviour, the technological level of cars, just to name a few elements that influence the road mobility demand - both in qualitative and quantitative terms. Automobile fuel economy standards have proven to be one of the most effective tools in controlling oil demand and greenhouse gas emissions from cars and any vehicle in general. The European automotive industry is currently committed to reducing new passenger vehicle CO2 emissions through a voluntary agreement with the European Commission. Factors like engine technology and fuel evolution, consumer choice, the length of implementation lag of prevailing legislative or fiscal measures that influence vehicle purchase and use, can be simulated in order to understand how and when they will affect fuel demand and any resulting CO2 emissions mitigation. Analyses, from a dynamic point of view, of such a heterogeneous framework are becoming increasingly puzzling and simulations can be extremely useful to capture the main trends. Toward Integrated Assessment of Technology and Policy Alternatives for Materials Use Heui-Seok Yi and Bhavik R. Bakshi Department of Chemical and Biomolecular Engineering, Ohio State University, Columbus, OH 43210 USA E-mail: bakshi.2@osu.edu, bakshi@chbmeng.ohio-state.edu Successful development and execution of industrial products and processes requires consideration of economic, environmental and social factors that span multiple spatial and temporal scales. For example, engineering decisions are made at a fine scale of individual equipment and process, while its implications are felt at much coarser scales of the economy and ecosystems. In contrast, policies are made at a coarse scale, but its effects are felt at finer scales. Most methods for technology assessment and policy analysis tend to focus on one primary scale. For example, Life Cycle Assessment focuses mainly on the scale of the value chain (supply and demand chains), while Economic Input-Output and General and Partial Equilibrium Models focus on a macroeconomic scale. Most existing research on modeling the relationship between the economy and environment has focused on energy use. The main goals of this talk are to motivate the need for integrated multiscale modeling of economic, industrial and environmental systems, and to discuss potential approaches for satisfying this need. An approach for integrating economic input-output models with engineering process models will be described. Illustrative examples based on this model will demonstrate its use for studying the effect of carbon taxes across scales. An economic input-output (IO) model is used to calculate price changes, and a fundamental model based on thermodynamic conservation laws is utilized for a production plant. The results by the proposed method are compared with those by traditional engineering optimization approaches that ignore price changes in other sectors of the economy. New challenges and areas of further research will be identified, including opportunities for integrating thermodynamic analysis with economic modeling. A general multiscale stochastic modeling framework will be proposed for reaching these goals. A multi-scale integrated assessment of the energy sector in Romania Raluca Iorgulescu Polimeni Economics Department, Siena College, 515 Loudon Road, Loudonville, New York 12211, USA, rpolimeni@siena.edu John M. Polimeni Albany College of Pharmacy, 106 New Scotland Avenue, Albany, New York 12208-3492, USA, polimenj@acp.edu Using the Multi-Scale Integrated Analysis of Societal Metabolism (MSIASM) approach and information from various sources for social indicators and economic data this paper will examine the energy sector of Romania. As an economy that is transitioning from a communist command economy to a market economy, Romania provides an interesting example of a structural change of an economy, particularly for the energy sector. During the communist period, Romania’s economy, like most other communist countries, relied heavily on the industrial sector, which was very energy intensive. After the 1989 Revolution and a return to a market economy, Romania moved towards a more dynamic service sector and away from a reliance on the high energy consuming industrial sector. This paper will use the MSIASM approach to discuss the structural changes in Romania’s economy. Furthermore, scenarios will be conducted using the MSIASM to provide an analysis of the energy sector and to examine plausible alternative energy sources as Romania’s economy continues its economic transformation. Multi-Scale Integrated Assessment of Sustainability in Latin America – a comparison of different trajectories of development for different countries Jesus Ramos-Martin, Nina Eisenmenger, and Heinz Schandl jesusramosmartin@yahoo.es Recent economic transitions in Latin America’s developing economies face a different development context than those experienced in history by today’s developed economies. The current transitions are integrated in a global economic system where the global division of labour assigns each country a specific role. Thus, socio-economic development within a developing country is not only dependent on internal processes, but is also strongly influenced by international processes. Our contribution focuses on three Latin American countries (Brazil, Venezuela, and Chile) and takes a comparative view. We describe biophysical aspects of these economies (energy- and material throughput, use of land and time) in order to analyse different paths of transition in socio-economic development and resource use. In history, the agricultural sector has created the initial impulse for sustained economic growth and the shift to industrialization of Europe. We will start the analysis in Latin American countries by identifying major trends in agricultural development to understand the specifics of today’s economic transition. A considerable proportion of agricultural production in South America was taken over by large companies already quite early, around 1900, and the rural population’s choice was either to be employed in agricultural wage labour or to move to urban centres in order to make a living. Despite the industrialization of large parts of agricultural production, agriculture, for different reasons, failed to generate a sufficient amount of economic added value to support industrial production and manufacturing. Instead, international capital from foreign direct investment and loans was supporting the development of the second and third sectors. However, structural adjustment programs as well as foreign investments (as promoted by the World Bank and the International Monetary Fund) primarily aim at intensifying the integration of these economies into the world market, and at enlarging production for exports. These interventions from abroad often went hand in hand with economic liberalization characterized by weak labour regulation, by lifting of trade tariffs and by opening local markets to both foreign capital and goods. The exports a country specializes in depend on the available resources and on technical potentials. South America has a long history in providing raw materials to the United States and other industrial centres, specializing in intense extraction of natural resources from mining and agriculture for exports. In the literature, the concept of extractive economies tries to capture the adverse effects exporting of raw-materials has on the social system and the local households as well as on the integrity of the environment and the exploitation of resources. Based on recent empirical data for biophysical and socio-economic aspects of development in Latin America we identify what enables or constrains certain futures. We discuss that in order to understand the potentials for a sustainability transition in the region we need to locate the current transition within a much older transition, namely the fundamental change in society-nature interrelation when society’s move form agricultural metabolism to a new industrial pattern. Keywords: Development, Integrated Assessment, Latin America, Material Flows, Societal Metabolism, Multi-Scale Analysis Assessing the suitability of input-output Analysis for enhancing our understanding of potential effects of Peak-Oil Christian Kerschnera, Klaus Hubacekb Institut de Ciència i Tecnologia Ambientals, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain. Tel 93 581 29 74, Fax: 93 581 33 31, Email: christian.kerschner@gmail.com b School of Earth and Environment, University of Leeds, Leeds, LS2 9JT, UK Input-output analysis developed from a purely economic tool to a standard approach for analyzing environment – economy interactions and whole supply chain effects in areas such as ecological economics, life-cycle analysis and industrial ecology. The standard Leontief type IO analysis allows analyzing the direct and indirect effects of exogenous demand changes upon an Economy, which makes it essentially a demand-driven model. Therein it is implicitly assumed that all necessary inputs to satisfy a given demand can and will be supplied. In other words the application of this model is problematic if the availability of certain key inputs becomes restricted. Thus it is argued here that it is not suitable for analyzing the phenomenon of peak oil, which was first highlighted by King Hubbert in 1956. This paper considers one by one the suitability of three alternative modelling tools within the IO framework: supplydriven and constrained IO models and linear programming in combination with IO modelling. The supply-driven IO approach was brought forward by Gosh (1958) and empirically applied for resource shortages already (e.g.: Chen and Rose 1985). However this approach was exposed as implausible by Oosterhaven (1988), as an increase in value added (e.g.: labour) in one sector induces increases in outputs in all sectors, even in those where value added remains unchanged. At a later stage, it was shown that the Gosh model can be reinterpreted as a price model and in fact yields exactly the same results as the Leontief price model (Dietzenbacher 1997). However the price model is not useful to the kind of tool we set out to encounter either, as the link to final demand is missing. Linear programming in combination with IO analysis can be useful in order to decide which sectors are most important to maximize a predetermined goal e.g. output or welfare. This however is more of interest as a planning tool once Peak Oil has either become reality already or the desirability of anticipatory policies to counter its possible detrimental effects becomes widely acknowledged. The most promising tool for our purpose, so it is argued here, is a supply constrained IO model. It is shown how such a model can account for constraints in the supply of fossil fuels,, by taking the total output of the petroleum sector as exogenously given. Consequently the model is applied to data for the UK economy to show the potential effects of a peak-oil induced supply shock to the UK, followed by a cautious interpretation of the results. Keywords: Input-Output Analysis, Supply-Driven and Supply Constrained IO Analysis, Linear Programming, Peak-Oil, Leontief price model, systems approach. a Extended Exergy as an ecological indicator: some preliminary considerations Enrico Sciubba Department of Mechanical & Aeronautical Engineering University of Roma 1 “La Sapienza” enrico.sciubba@uniroma1.it The study of Very Complex systems (“VLCS”) requires a holistic approach to analyse the entire system and all of the “external” and “internal” interactions that characterise it. The best way to approach such problems is to consider the VCLS as an “extended” (in a sense to be specified later) thermodynamic system. The evaluation of the flows of matter and energy sustaining a VCLS and the knowledge of the transformations therein can be used to describe the rate of exploitation of the available natural resources. This kind of information could be an important support for both the internal and global policy planning and resources management. In the last decade, environmental scientists, engineers, physicists, chemists and biologists have defined, troubleshooted and calibrated a number of “decision parameters”, called ecological indicators (EI in the following), that ought to be used by National & International Agencies in their evaluations. In the often heated debates that arose from the discussions about the applicability of each one of these EI, it became clear that there is the necessity of defining ecological indicators in such a way that they may convey at the same time some quantitative and qualitative information. This is not an easy task, and several EI have been proposed that for one reason or another lack the necessary sharpness. This paper is concerned with one of these EI’s, Extended Exergy, which is a measure of the irreversibility of natural and anthropogenic processes. It is argued that a material balance, per se, cannot be a good EI: it provides a measure of the throughput of a certain sector of the society -or of the society as a whole- but it cannot properly measure the intrinsic quality of that throughput. For example, none of the “material flow” methods can indicate whether it is better to generate electricity by coal-fuelled or nuclear powerplants, because a “mass-flow based” EI is unable to capture the diversity of the coal- and uranium life cycles. Also the methods based on an energy analysis (embodied energy, emergy) are only marginally effective and even misleading in their descriptions of the inputs & outputs of a territorial or of an industrial system, because they cannot discern between “low quality” (heat) and “high quality” (mechanical work, electricity) energy flows. In the early ‘80es Gøran Wall and others presented the first complete analysis of territorial system based on exergy flows that, in contrast to energetic studies, explicitly included both First- and Second thermodynamics Law. This approach makes it possible to express any kind of system’s input, either energetic or material, on a uniform thermodynamic scale, so that these inputs (and the corresponding outputs) can be “normalized” and evaluated by attributing to each one of them an exact value of “work content”. It can be though shown that exergy destruction, which is indeed a direct measure of the irreversible entropy generation of a process, is not a completely acceptable EI, because it cannot properly account for toxicity-related chemical pollution. Recently, an extension of classical exergy analysis called Extended Exergy Analysis (EEA) was presented by the Author. This method seems appropriate to investigate industrial and territorial system alike, because it can compare the physical flows of energy and matter with non-energetic quantities like capital, human labour and environmental impact (quantified by necessary environmental remediation costs). Models for splitting the exergy destruction into endogenous and exogenous parts George Tsatsaronis*, Tatiana Morosuk§ and Solange Kelly Institut für Energietechnik, Technische Universität Berlin, Berlin, Germany E-mail:* tsatsaronis@iet.tu-berlin.de , § eao1_1@buran.fb10.tu-berlin.de The irreversibility within a component of an energy conversion system can be represented by two parts. The first part depends on the inefficiency of the considered component and the second depends on the system structure and the inefficiencies of the other components of the overall system. This fact was described by many authors, however missing aspects of the theory did not allow the division of the irreversibility into the above described parts. The total exergy destruction occurring in a component can be split into two parts: (a) endogenous exergy destruction due exclusively to the component being considered and (b) exogenous exergy destruction caused by inefficiencies with the remaining components of the overall system. The endogenous part of exergy destruction in a component within a system is the exergy destruction that occurs in the component when all other components of the overall system have an ideal performance (exergetic efficiency of 100 %). The exogenous part of exergy destruction is the difference between total and endogenous exergy destruction. Such splitting of the total exergy destruction improves the accuracy of exergy analysis, improves our understanding of the thermodynamic inefficiencies, and facilitates exergoeconomic optimization. The paper will discuss various approaches for calculating the endogenous and exogenous parts of the total exergy destruction. The advantages, disadvantages and restriction for applications associated with each approach will be presented. Eco-Exergy: Reductionistic or Holistic Approaches Roberto Pastres Dipartimento di Chimica Fisica, University of Venice, Italy Brian D. Fath Biology Department, Towson University, Towson, MD 21212 USA bfath@towson.edu We explore the historical development of exergy in ecology, highlighting its differences from that in engineering, as well as speak to the limitations of the current ecological formulation and provide direction for future work. As a foundational thermodynamic property regarding the amount of useful work available in a system, exergy has found application in analyzing ecosystems. In particular, Exergy Degradation and Exergy Storage have been used as ecological orientors and total exergy as an ecosystem indicator. The difficulty is defining what exactly one means by exergy of a living system. The primary differences between ecological exergy (now referred to as eco-exergy) and engineering exergy deal with the reference state and the consideration of organizational contributions. Regarding the first issue, rather than thermodynamic equilibrium, eco-exergy uses the system at the same temperature and pressure but without life (i.e., the inorganic primordial soup) as a reference state. Furthermore, in addition to the strictly thermodynamic work, eco-exergy includes information contained in living material. In other words, a certain mass of dead organic material can do less work than the same amount of living material. Currently, the amount of “informational” work is calculated based on the genetic complexity of the organism, but this is a fluid area of research. Here, we suggest the inclusion of network structure as an information contributor to provide a more holistic accounting of the how organisms are embedded in their system. Accounting the Earth’s mineral capital for the most demanded minerals in the industry Amaya Martínez (*), Antonio Valero, Inmaculada Arauzo and Alicia Valero Fundación CIRCE. Center for Research of Energy Resources and Consumptions. Universidad de Zaragoza. María de Luna, 3. 50018 Zaragoza. Spain. Phone: +34 976 76 18 63 Fax: +34 976 73 20 78 * Corresponding author: agracia@unizar.es Earth’s mineral resources have been previously evaluated(1) in physical units using the concept of the exergetic replacement cost. This methodology is based on the thermodynamic evaluation of the minimum exergy needed to produce all mineral resources under the physical and chemical conditions that make them useful. The reference environment(2) taken is a thermodynamically dead planet where all materials have reacted, dispersed and mixed. Interesting results were published by Antonio Valero, Lidia Ranz and Edgar Botero under the title “An exergetic assessment of natural mineral capital: reference environment, a thermodynamic model for a degraded earth”. The real physical unit cost of a mineral was defined as the relationship between the energy invested in the real process of obtaining it and the minimum energy required if the process were reversible (that is, its exergy). Results obtained for the 42 evaluated minerals show that the exergy unit cost is tens or even hundreds of times grater than its exergy content. These results allow us to range minerals according to their exergy cost. The described methodology has been now applied to the main mineral substances that are commercially exploited. Substances such as chrome are generally used in the industrial processes as Chromite (FeCr2O4); Manganese is usually exploited as Silicomanganese (SiMn) and Ferromanganese (FeMn); or fluor, whose main application is under its fluorhydric acid (HCl) form. In this paper the exergy cost of several representative substances for the industry will be evaluated. 1) Botero, E. (2000) Valoración exergética de recursos naturales, minerales, agua y combustibles fósiles. Tesis doctoral. Departamento de Ingeniería Mecánica. Universidad de Zaragoza. (2) Szargut, J.; Valero, A.; Stanek, W.; Valero D., A. (2005) Towards an international legal reference environment. Presented for ECOS 2005. Trondheim, Norway. Thermodynamics-based indicators as tools for evaluating sustainability of land-based aquaculture in Central African Republic I.Beiso a,*, R.Pastres b, A.Palla c, P.Letizia c a b School for Advanced Studies in Venice Foundations, Island of San Servolo, Venice, Italy. Department of Physical Chemistry, Universita` di Venezia, Dorsoduro 2137, Venice, Italy. c Ingegneria Senza Frontiere di Genova. Via Dodecaneso, Genova Italy. *E-mail: ilaria.beiso@unive.it In recent years in developing countries aquaculture has assumed an important economic and social role for local communities, as it can provide food, income and employment opportunities. Nevertheless, aquaculture, like other activities that use natural resources, often causes a deterioration of the supporting environment, as well as some conflicts between aquaculture operators and local population. In order to be sustainable, acquaculture activities should take into account the role of ecosystem resources, considering also economic aspects. This paper presents a preliminary analysis, aimed at assessing the sustainability of aquaculture activities on the Pama’ river, Central African Republic and at suggesting improvements to the original project. This analysis was undertaken in the framework of a pilot project, which is being developed by the local NGO (CEDIFOD) and Ingegneria Senza Frontiere of Genova. The analysis was conducted by quantifying the fluxes of material and energy exchange at steady state between the aquaculture system and the surrounding environment in terms of two thermodynamics-based indicators, Emergy and Exergy. These indicators allow one to take into account both the quantity and quality of energy and, therefore, to compare the environmental and antropogenic fluxes. The study was carried out by using site-specific environmental data, which were collected in the framework of this research project, and information about the structure of the farm and the hausbandry practises, based on the farm design. Though incomplete, this data set permitted to estimate the themodynamic indicators, thus demonstrating the applicability of the approach here proposed also in developing countries. These indicators were compared with those relative to the analysis of a semi-natural extensive aquaculture farm in the Figheri basin in the Lagoon of Venice, Italy, in order to evaluate the sustainability of the farm. Despite the different characteristics of the two situations, the comparison provided usesul insights for assessing the sustainability of the acquaculture project in Central African Republic. A systemic water quality model of Mogi-Guaçu river in SP, Brazil Marlei Roling Scariot and Enrique Ortega Postal address: FEA - Unicamp, Caixa Postal 6121 CEP 13.083-862 Campinas - SP – Brasil. Telephone number: +55(19)3788-4035, Fax number: +55(19)3788-4027, e-mail: ortega@fea.unicamp.br A new trend in basins planning in many countries is to use water quality model simulation to evaluate the environmental impacts. The main goals of this work are the assessment of nitrogen, phosphorus, dissolved oxygen and biomass and to find out the origin, transport and its dynamic behavior. The proposed hydrologic model is a system based on completely mixed reactors in series. Each volume of control is described individually by a differential equation system from mass and energy balances. The mathematic model assumed is from the systemic diagram and allows the dynamic simulation of the water quality indicators. The model calibration is done by means of comparison with a historic experimental data series from CETESB (Governmental Technology Company of Environmental Sanitation). After the model simulation, calibration and validation, scenarios were created in order to help the understanding of the possible future conditions for the river, taking into account the alternatives of environmental policies, populations and economic grow. The combined results from the simulation and thematic map from geographic information system (GIS) make possible to evaluate the main cause of water quality impacts in the Mogi-Guaçu river SP/Brazil. Keywords: model, system, basin, water quality. Thermodynamic approach for the assessment of sustainability of small marinas Chiara Paoli, Paolo Vassallo * and Mauro Fabiano § Department for the study of the territory and its resources University of Genoa Corso Europa 26, 16132 ITALY * paolo.vassallo@unige.it § fabianom@unige.it The construction and the activity of a marina in the context of coastal zone could entail some potential detrimental effects on the marine environment. Tourist pressure and small marina activities have many interactions with the surrounding environment and a complete and integrated approach to the quality concept and to the assessment of the level of sustainability could reveal some important aspects of the problem. It is essential to give operative and economically adequate answers to the various demands of the parts involved in the system. For this purpose emergy analysis, considering both environmental and economic aspects of sustainability seems to be an interesting approach. Emergy is a thermodynamics-based function defined as the available energy of one kind previously used up directly and indirectly to make a product or service. In this study, the emergy concept was used to evaluate the sustainability of the activities deriving from the management of the marinas setting up a schematic model for the application of this kind of analysis to a typical Mediterranean tourist harbor. The approach has been applied to a study case: the “Marina degli Aregai” small harbor in the western Ligurian coast (Italy, Northwestern Mediterranean). The adaptability of the analysis allows further comparison with other marinas in the same geographical area to detect the relevance of different management practices and with marinas in areas with different natural conditions to detect changes due to the variations in external constrains. Emergy balance assessment in three landscape units in the north Adriatic sea Leonardo Marotta* and Diego Marazza** * Entropia Snc and AISA Scientific Committee, leo.mm@libero.it ** CIRSA:– University of Bologna, via S.Alberto 163 48100 Ravenna (Italy), diego.marazza@unibo.it Landscape is defined as a domain, but also as a system and finally as a unit. The landscape domain represents the field in which natural and human processes take place and create the observed patterns. In the Mediterranean area geo- and ecosystems have been deeply shaped by anthropogenic factors forming a highly diverse mosaic of disturbancedependent land/seascapes. In this paper landscape ecology and emergy analysis are integrated in order to assess the emergy balance of three different landscape units at the water-land interface and at critical points in the north Adriatic area (Italy): a coastal area, a river basin and a lagoon. The emergy of manmade protection infrastructures and the emergy of the corresponding human activities at the land unit scale has been assessed. The method is applied with special reference to the european water framework directive. Energy technology perspectives 2030-2050: A key driver for innovative policy to accelerate renewable deployment Roberto Vigotti IEA Chairman Renewable Working Party roberto.vigotti@inergia.it Secure, reliable and affordable energy supplies are fundamental to economic stability and development. The threat of disruptive climate change, the erosion of energy security and the growing energy needs of the developing world all pose major challenges to energy decision- makers. They can only be met through innovation and the adoption of new costeffective technologies and better use of existing energy efficient technologies. Energy Technology Perspectives presents status and prospects for key energy technologies and assesses their potential to make a difference by 2050. It outlines the barriers to their implementation and measures to overcome them. The Outlook to 2050 and the Role of Energy Technology The world is not on course for a sustainable energy future. Oil prices at historical highs raise concerns about the longterm supply-demand balance. CO2 emissions have increased almost 20% over the last decade. Indeed, if the future is in line with present trends as illustrated by the World Energy Outlook 2005 Reference Scenario, CO2 emissions and oil demand will continue to grow rapidly over the next 25 years, even taking account of energy efficiency gains and technological progress that can be expected under existing policies. Extending this outlook beyond 2030 shows that these worrisome trends are likely to get worse. In the Baseline scenario developed for this study, CO2 emissions will be almost two and a half times the current level by 2050. Strong growth in transport demand will continue to put pressure on oil supply. The carbon intensity of the world economy will increase due to greater reliance on coal for power generation – especially in rapidly expanding developing countries with domestic resources -- and increased use of coal in production of liquid transport fuels. But this outlook can be changed. The Accelerated Technology Scenarios (ACTs) presented in this study demonstrate that by employing technologies that already exist or are under development the world could be brought onto a much more sustainable energy path. The scenarios show how energy-related CO2 emissions can be returned to their current levels by 2050 and how the growth of oil demand can be moderated. They show that by 2050, energy efficiency measures and renewables can reduce electricity demand by a third below the Baseline levels The substantial changes demonstrated in the ACT Scenarios come as a result of strong energy efficiency gains in transport, industry and buildings; of electricity supply becoming significantly de-carbonised as the power generation mix shifts towards nuclear power, renewables, natural gas, and coal with CO2 Capture and Storage (CCS); and through increased use of biofuels for road transport. Nevertheless, even in the ACT scenarios, fossil fuels still supply most of the world’s energy in 2050. To that extent, this is an evolutionary rather than a revolutionary change. Demand for oil, coal (except in one scenario) and natural gas are all greater in 2050 than they are today. Investment in conventional energy sources thus remains essential. The five ACT scenarios all have the same underlying assumptions about strong growth in energy service demand.. A sixth scenario, Tech Plus, illustrates the implications of making more positive assumptions on the rate of progress for renewables technologies as well as for advanced biofuels and hydrogen fuelled fuel cells for the transport sector. There are large uncertainties when looking 50 years ahead. The ACT scenarios illustrate a range of possible outcomes based on assumptions that are more or less optimistic with regard to the cost reductions achieved by technologies such as renewables, nuclear and CCS in power generation. Yet, despite all the uncertainties, two main conclusions from the analysis seem robust. First, technologies do exist that individually can make a significant difference over the next two to five decades. Second, none of these technologies can make a sufficient difference on their own. A portfolio of technologies will be needed and no promising option should be excluded. Pursuing a portfolio will also greatly reduce the risk and potentially costs if one or more technologies fail to make the expected progress. The ACT scenarios point to the following technologies as key elements in a portfolio adopted for a sustainable energy future. Implications for renewable energy policies and mechanisms This also thanks to renewable energy, which has made very significant progress over the last three decades. Through R&D – much carried out through international collaboration – a number of sustainable technologies have advanced and are gaining a growing market share while contributing significantly to energy supply. Hydroelectricity provides almost 20% of global electrical generation while bioenergy and geothermal contribute significant amount of both electricity and heat. Newer technologies such as wind and photovoltaics are becoming important global industries with annual sales of several billion US$. The potential for renewable energy supply offers significant opportunities for further growth. Drawing on the experience of the last few decades and the lessons learned, it is clear that renewable energy can play a very important role in transitioning to a global sustainable energy supply by the middle of this century. Intelligent choice of priorities will invariably facilitate market deployment of new and improved technologies. To this end, it will be necessary to refocus the renewable energy strategy towards three general directions, They include: 1. Increased targeted renewables R&D funding; 2. Improved strategy for market deployment; and 3. Inclusion of externalities in policy considerations. R&D and market deployment complement each other and result in faster and more meaningful technology learning. In view of the impact of technology deployment policies in advancing the state of the art and expediting commercialisation, governments should seek new deployment policies that will facilitate renewables’ market growth. R&D and policy strategies need to differentiate among technologies in order to address diverse problems of particular and unique technical challenges. Renewable energy technologies have different development profiles but potential benefits may be similar in terms of more secure and diversified energy supply, economic development and reduced environmental impact (for example, hydro/wind/PV) International technology collaboration has provided proof that it can substantially contribute to the process of technological innovation. Many of the identified technology issues can be addressed through collaborative effort within the framework of the IEA. Integrating economic and emergy analyses in theory and practice Donald L. Adolphson, PhD * Romney Institute of Public Management 760 TNRB Brigham Young University Provo Utah USA 84602 801 422 2433 adolphsond@yahoo.com Daniel Campbell, PhD U.S. Environmental Protection Agency Office of Research and Development National Health and Environmental Effects Research Laboratory Atlantic Ecology Division Narragansett, RI 02882 401 782 3195 This paper provides a fresh perspective on a long history of using the model of natural science to gain insights into the workings of an economy. Economics relies heavily on the concept of utility, or usefulness, as an underlying basis for determining value. Usefulness implies a subject (individual, community, or society) that derives satisfaction from using an item. This emphasis on utility has led economists to think of their discipline as a receiver-based theory of value. Conversely, emergy accounting focuses on the energy transformations required to produce a given product or service as the means for determining its value. This emphasis on the production process has led many to think of emergy synthesis as a donor-based theory of value. In this paper, we show that, when viewed from an energy systems perspective, emergy is actually an objective measure of utility which complements well the subjective measure of utility oft used by economists. We show that emergy is a more comprehensive measure of utility than money or exergy, because it more accurately captures the inherent quality (ordinality) of a good or service, which manifests in its use within the system in which it has evolved. Barriers to sensible energy saving solutions Harald Throne-Holst, Pål Strandbakken and Eivind Stø National Institute for Consumer Research, SIFO, Norway P.O Box 4692, Nydalen, 0405 Oslo, Norway +47 22 04 35 73, harald.throne-holst@sifo.no We observe barriers among consumers to solutions for energy saving that are considered sensible and rational. How can these barriers be understood, explained and finally overcome? In connection with the “energy price crisis” in Norway in the winter of 2003/2004, where the price of electricity spiked due to severe cold combined low water levels in reservoirs (Norwegian domestic electricity production is hydro powered) lead to a doubling of electricity prices over a relative short time period. This event turned attention to the potential of heat pumps in Norwegian households. Even though it has become something of a truth that you save money on these devices, Norwegian consumers appear reluctant to borrow money to install them. We believe there are 5 types of barriers to energy saving solutions: 1. Physical and structural barriers: Households are a part of society’s greater general physical structure. The overwhelming majority are connected to electrical, telecom, water and wastewater networks. The degree and character of freedom of actions for individual households are largely dependent on basic historical traditions, 2. Political barriers: Politicians create frameworks for household behaviour. They give laws, directives and develop regulations on national and European level. These laws and regulations are set into practice by political authorities. Thus, political authorities determine the potential for change, and freedom of actions for households. 3. Economic barriers: Some measures to reduce your household’s energy use will include economic investments. These may give a payback over time, but still they presuppose available economic funds in the household to be set aside for such investments. 4. Cultural-normative barriers: Not all ways of saving energy may comply with the culture you live in. Norway for instance has the world’s highest per capita energy use for lighting; a major contributing factor to this is related to the cultural aesthetics, which relates interior lighting and pools of light and shadow with a cosy atmosphere. 5. Individual-psychological barriers: Finally we all have our own limits to what we would do to achieve a goal like saving energy, which can have their origin in individual taboos, having their roots in own experiences or upbringing. The main elements in these barriers will be identified and discussed in an empirical analysis based upon focus groups among various group of households. Especially we will distinguish between ordinary, stable households and households who are in a transition process where they build, rebuild and repair houses and flats, or move from one residence to another. We will identify their windows of opportunities. Third Party Financing. New financial tools for energy efficiency Claudio Ferrari ESCO-Italia S.p.A. E-mail: ferrari@escoitalia.it http://www.escoitalia.it/ Issues of energy efficiency are closely linked to financial availability. The latter can be increased by good use of energy due to optimised process management. Third Party Financing (TPF) is an appropriate tool for funding of optimisation strategies without financial charge to final user. This is due to budget savings from increased energy efficiency and more appropriate allocation of financial resources made available. ESCOs (Energy Service COmpanies) are the new technical and market operators which make the TPF tool available to final users. TPF is regulated from European Union Directive 93/76/EEC, which is presently in course of replacement by the more recent Directive 2006/32/EC. Third Party Financing has already been included in the Energy Programme of the Italian Government as well as in several Regional Energy Plans. The TPF strategy is strictly related to the White Certificate market (efficiency certificates), which is already regulated by the Italian Directive DM 20/07/2004 as well as the above-mentioned EU Directive 2006/32/EC. Several examples of application of TPF to foster energy efficiency in Italy with special focus on space heating for the residential sector are presented and discussed. Financial return on investment in energy efficiency and renewable energies Paolo Sardi E.Capital Partners P.Sardi@e-cpartners.com http://www.ecpfinance.com/ Renewable energy: The backgroundThe time of oil and gas shortages is near to come and, as a result, obtaining electricity from alternative sources has become increasingly important. The global boom in renewable energy is underway and it is set to continue. Overall, strong growth rates are forecasted for “clean energy sources”. Markets are expected to grow from USD 16 Bio in global revenues in 2004 to more than USD 100 Bio by 2014 according to a report released by Clean Edge, an energy research and publishing firm. The share of renewable energy in total worldwide electricity production is 17.9%. Roughly 90% of that share is water power (16.2% of total electricity production), biomass 6% and the remaining renewable energy processes almost 4% [1]. Types of renewable energy Renewable energy is generally classified as commercial energy production or energy sources which are inexhaustible. Bioenergy: A low cost energy source that can be obtained from biomass, in particular wood straw maize, sugar beet, oilseed rape, biogas and plant oils. Its main advantages is the reduction of carbon dioxide emission into the atmosphere . Solar Power: Energy of the sun (nuclear fusion), which takes the form of electromagnetic radiation. Water Power: Energy of water currents, which can be converted into mechanical energy using suitable machines. Wind power: Is the kinetic energy produced by masses of air moving in the atmosphere. Geothermal: Geothermal heat is the heat stored in the upper layer of the earth’s crust. It describes both the energy produced by or stored in the earth. Fuel cells: A fuel cell is a voltaic cell that converts a continuous supply of fuel and an oxidising agent into usable electrical energy.Alternative Solutions: ECPI® (E.Capital Partners Index) selects global players active in implementing innovative solutions that allow a more efficient and environmental – friendly use of power resources.ECP Index Construction The ECP Renewable Energy Index includes a set of 30 global companies that aim at providing near-term solutions to global warming while offsetting the longer-term impacts of climate change through renewable energy, alternative fuels, clean technology and efficiency.Sector Validation Constituent selection is based on the Proprietary and Transparent ECPI Research Methodology. Nuclear energy or oil are not taken into consideration, except for the specific discretionary cases when a company can substantially contribute to the sustainable development and use of renewable energies. Inclusion of such companies will be explicitly communicated. SustainabilityECPI® evaluates each company eligibility based on its specific environmentally sustainable efforts, environmental management and capability to offset negative climate impacts. The highest ranked companies in each category are included in the Index such as those that record significant and forward looking achievements in the field of environmental friendly and sustainable products e.g. the world's first massproducer hydrogen-powered fuel cell hybrid vehicle. [1] Federal Ministry for the Environment, Nature Conservation and Nuclear Safety, June 2005, Germany Back to the Future: global convergence of Energetic, Environmental, and Economic Issues. Mark T. Brown University of Florida mtb@ufl.edu With the increased demands placed on material resources, land, water, and the environment in general, from continued economic development, population growth, and increasing standards of living, humanity is on a collision course with energetic, economic and environmental realities. All indications are that the global supply of fossil petroleum is limited and will soon peak in availability and begin declining. The net energy (or Energy Return on Investment) of primary energy sources will increase the effect of “Peak Oil” on the economy much sooner than predicted. Large global storages of coal will power economies, but dealing with greenhouse gases will decrease their net energy contributions. Renewable energy sources are dilute and require large spatial areas and significant material resources, reducing their net energy. Dealing with environmental impacts (ie global warming, pollution, decreased productivity of ecosystems) may further exacerbate the effects of declining fossil energy availability. The following questions (among others) will be posed and answered in this presentation: Can humanity heed warnings of economic calamity resulting from reduced energy availability? Can humanity reverse current trends of global warming? What is the minimum net energy (EROI) required of sources to sustain global economies? What is the relationship between the intensity of energy sources (ie specific energy) and their net energy? Can we increase the energy efficiency of the economy?