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April 2008 Bulletin IEA Ocean Energy Systems


Ocean Energy - Wave Energy - Rewable Energy -

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									     NEWSLETTER                                             National Activities
                  April 2008               ISSUE 10

National Activities - Nereida MOWC - Spain - 1
                                                            NEREIDA MOWC
                                                            by Luis Villate Martinez, Robotiker, Basque Country, Spain
National Activities - Tidal Power - United Kingdom - 2      NEREIDA MOWC is a demonstration project involving the integration of an
National Activities - Osmotic Power - Norway - 3            Oscillating Water Column (OWC) system with Wells turbines in the new
Forthcoming Events - 4                                      rockfill breakwater at the harbour in Mutriku on the Basque coast in Spain.
Wave Data Catalogue - 4                                     The facility will generate power that will be directly fed into the power grid.
                                                            Unlike other demonstration facilities, this one will be located in an urban
                                                            setting-Mutriku (pop. 4,800), which has a long seafaring and fishing tradition.
Editorial                                                   The project was first raised when the Basque Government's General Ports
                                                            Office, which is in charge of building the new breakwater in Mutriku, consulted
                                                            the Basque Energy Board about the possibility of harnessing energy in the
The year 2008 is bringing again good prospects for
Ocean Energy exploitation.

It should be noticed that this issue of our Newsletter
                                                            Following relevant studies (e.g. analysis of technologies, assessment of the
includes projects regarding the conversion of three         resource, structural calculations and breakwater stability tests) it was decided
different ocean energy sources: wave energy, tidal          to install a multi-chamber system, making the Mutriku facility the first
energy and salinity gradient energy. It is interesting to   breakwater in Europe to integrate this technology and adopt this design
note that the Spanish project to convert wave energy        arrangement.
using Oscillating Water Column converters imbedded
into a breakwater is a new application of this type of      Specifically, it consists of 16 oscillating water columns or chambers, forming
systems that presents the advantages of decreasing the      a total collector length of approximately 100m, in which 16 Wells turbines
investment and avoiding the need to look into the
                                                            will be installed (one per OWC). Each turbine will have a rated capacity of
environmental impact caused by the coastal structure.
                                                            18.5 kW, giving a total installed capacity of 0.3 MW. The facility will also
                                                            contain control and power adaptation equipment, a transformer and a line
The decision to carry out studies for the construction
of a tidal barrage in the UK Severn estuary (that started   connecting to the power grid.
to be considered more than two decades ago) indicates
that this project is probably approaching deployment.       The plant will be supplied turnkey by Voith-Siemens Tolosa. The technology
This is the first time that this mature renewable energy    is being developed by Wavegen, also a member of the Voith-Siemens group.
technology is considered in Europe after the 240 MW         The plant has an anticipated annual production capacity of 600,000 kWh-
French La Rance plant started operation in middle           equivalent to the domestic power consumption of 600 people.
1960s.                                                      One of the unusual features of the Mutriku facility is that it will be integrated
                                                            into a rockfill breakwater; this requires a new technique for building the
Finally, the Norwegian project to convert osmotic
                                                            structure, using prefabricated parts placed outside the rock filling. In addition,
pressure due to salinity gradient into useful electrical
                                                            developing a collector structure with various chambers gives the structure
energy is a very new technology with great potential for
electrical energy supply at the global level.
                                                            greater solidity than would be the case with an equivalent single-chamber
                                                            system. It also reduces construction costs.
The Wave Data Catalogue that has now been edited is
certainly a useful tool for those who are interested in     As an innovative demonstration project, Mutriku project has been selected
assessing the wave energy resource.                         by the European Commission to receive funds under the Sixth Framework
In addition to these new ocean energy projects, we are
happy to announce that after Spain and New Zealand          NEREIDA MOWC will demonstrate the technical and economic viability of
have joined the IEA-OES, its members have increased
                                                            integrating OWC facilities into piers and breakwaters and will substantially
to 14.
                                                            contribute to rolling out marine energy technology in Europe.

Teresa Pontes
Portuguese Delegate
First IEA-OES ExCo Chair

                                                                          Aerial view of the NEREIDA MOWC construction site
National Activities

Severn Tidal Power Study Could Unlock                                                                    "We must understand the cost and the impact that a project of this scale

Massive Renewable Potential                                                                              could have, not least the environmental, social and economic effects. But the
                                                                                                         need to take radical steps to tackle climate change is now beyond doubt.
by Gary Shanahan, Department for Business, Enterprise and Regulatory
                                                                                                         Tough choices need to be made. We must consider all our low carbon energy
Reform (BERR), United Kingdom                                                                            options."

The massive potential for tidal power from the Severn Estuary to provide                                 The study, which will include a Strategic Environmental Assessment, is
low carbon, renewable electricity was highlighted by Energy Secretary,                                   expected to last roughly 2 years. It is expected to conclude with a full public
John Hutton, with the publication of the terms of reference for the                                      consultation in early 2010. The work will be done by a cross-Government
Government's feasibility study on 22 January 2008.                                                       team, also involving the Welsh Assembly Government and the South West
                                                                                                         Regional Development Agency, bringing together expertise from a number of
Tidal barrages and lagoons will be looked at in the feasibility study                                    o r g a n i s a t i o n s a n d e n g a g i n g s ta k e h o l d e r s a n d t h e p u b l i c a t l a r g e .
which will analyse the potential environmental, social and economic
impacts of the possible projects. It will enable the Government to decide                                Building on the work of the Sustainable Development Commission and earlier
whether and on what terms it could support a tidal power project.                                        studies, the feasibility study will:

One of the possible technologies, a Severn Barrage, would harness                                        - assess in broad terms the costs, benefits and impact of a project to generate

the power of the Estuary using the proven technology of a hydro-electric                                 power from the tidal range of the Severn Estuary, including environmental,

dam, but filled by the incoming tide rather than by water flowing                                        social, regional, economic, and energy market impacts;

downstream. Such a project, as the recent report from the Sustainable
                                                                                                         - identify a single preferred tidal range project (which may be a single
Development Commission confirmed, has the potential to generate
                                                                                                         technology/location or a combination of these) from the number of options
some 5% of UK electricity from a renewable British source.
                                                                                                         that have been proposed;

John Hutton said:                                                                                        - consider what measures the Government could put in place to bring forward
"The potential scale of this project, and the impact it could have for                                   a project that fulfils regulatory requirements, and the steps that are necessary
b o t h s e c u r i n g e n e r g y s u p p l i e s a n d ta c k l i n g c l i m a t e c h a n g e i s   to achieve this; and, decide, in the context of the Government's energy and
breathtaking. The Severn Estuary has some of the best tidal potential                                    climate change goals and the alternative options for achieving these, and
in the world and could more than double the current UK supply of                                         after public consultation, whether the Government could support a tidal power
renewable electricity, and contribute significantly to targets for renewable                             project in the Severn Estuary and on what terms. The workplan for the
energy and CO 2 emissions reduction.”                                                                    Feasibility Study can be found below.
National Activities

Osmotic Power                                                               Given sufficient control of the pressure on the salty water side, approximately
                                                                            half the theoretical energy can be transformed into electrical power, making
by Stein E. Skilhagen and Jon Dugstad, Statkraft, Norway
                                                                            osmotic power a significant new renewable energy source.
Osmotic Power stands out as a promising and yet unexploited, new
renewable energy source. Throughout the last years, developments have       The illustration above shows salty water pumped from the sea and filtered before
led to believe that it is possible to develop the necessary membrane        it is pressurised and fed into the membrane module. In this module it is diluted
technology and the building of the first osmotic power prototype plant is   by the water received from the less salty side of the membrane. The osmotic
being planned in 2008. A wide R&D programme involving research              process increases the volumetric flow of high pressure water which is the key
centres and commercial developers on three continents are part of the       energy transfer in the power production process.
plan.                                                                       The diluted and now brackish water (dark blue) that exits from the membrane
                                                                            module is utilised to generate power and to add pressure to the feeding of salty
                                                                            water. Optimal operating pressures enables the generation of 1 MW per m 3 s
                                                                            fresh water.
Osmotic power is a relatively new energy conversion concept even
though osmosis has been known for several hundred years. Only               The development of a membrane especially designed for PRO has been the
30-35 years ago Prof. Sidney Loeb and his team at UCLA utilised             main challenge since the very beginning of the project. While membrane
the existing knowledge and proposed methods for the utilisation of          developers have been able to achieve significant power efficiencies lately, a
osmotic pressure in power generation using membranes.                       commercial membrane is yet to be developed.

In the eighties and nineties, membrane technology was introduced            To enable osmotic power convertion, much of the technology used today by the
successfully in many industrial applications and efficient semi-            hydropower and the desalination (water) industries can be utilised with small
permeable membranes became available. In the late nineties the              modifications.
efficient transfer of mechanical energy between fluids was also
made possible. All the basic technology components necessary for            The Energy Potential
efficient osmotic power production are therefore in principle available.
New and more energy efficient membrane technology has been                  The major technical prerequisites of osmotic power plant sites are 1) steady
developed during the last few years.                                        availability of fresh water and sea water b) available building site at or beneath
                                                                            the surface. Such sites are envisaged at river mouths, outlets from hydropower
The commercial potential of osmotic power is identified and Statkraft,      stations or outlets from cleaned wastewater drainage situated close to the ocean.

a North European electricity generator, is now planning to build an
                                                                            The osmotic power potential in Europe is estimated to ca. 180 TWh/year, while
osmotic power plant prototype to further verify the osmotic power
                                                                            the potential in the Rest of the World is roughly estimated to ca. 14-1500
                                                                            TWh/year. Hence, the total estimated potential for osmotic power is estimated
                                                                            to ca. 16-1700 TWh, in line with the combined annual supply in Germany, France,
The Power of Osmotic Power
                                                                            Spain and the UK. Only the availability of fresh water will limit the potential of
The principle of osmotic power is based on utilisating the entropy          osmotic power.
of mixing water with different salt concentration. In this process
water is transported spontaneously through a semi-permeable                 The competitive pricing range for osmotic power is expected to be EUR 50-
membrane (i.e. a membrane that retains the salt ions but allows             100/MWh, taking into account public support schemes available similar to those
water through it) from the side with the water with low salt                available to other renewable energy technologies today. Statkraft expect that
concentration to the water with the higher salt concentration thus          the cost of osmotic power production will be in line with the cost of wind offshore
creating increased pressure due to the osmotic forces. Given a              and below wave and tidal power generation in 2015. Osmotic power is a highly
fixed volume compartment on the saltier side, the pressure will             sustainable renewable energy source and therefore expected to receive support
increase towards a theoretical maximum of 26 bar considering                similar to that received by wind and solar power today. It is believed that
Atlantic sea water.                                                         supported osmotic power will be competitive compared to other renewable energy
                                                                            sources, such as wind, tidal, wave and to a certain degree also hydro power.
Pressure retarded osmosis (PRO) is the most promising method
for conversion of this energy. The basic scheme is sketched below.          The capital cost of installed capacity is high compared to other renewable energy
                                                                            sources such as wind. Each MW installed is however very productive. While a
                                                                            wind mill is designed to operate in average 3.500 hours/year at various ca-
                                                                            pacities, an osmotic power plant is believed to operate at full capacity for more
                                                                            than 7000 hours a year.

                                                                            Osmotic power stands out as a promising and yet unexploited new, renewable
                                                                            energy sources. After proof of concept in the prototype expected be operational
                                                                            in 2009, a full scale demonstration plant and commercial introduction is expected
                                                                            to follow in the next 5-7 years.
Agenda Events on Ocean Energy                                                    IEA - OES Reports

                                                                                 Wa v e D a ta C a ta l o g u e
                                                                                 André Candelária and Teresa Pontes, INETI / LNEG, Portugal
Global Marine Renewable Energy Conference
New York, USA, April 17 - 18, 2008                                               A Wave Data Catalogue for wave energy resource assessment in IEA-OES Member
                                                                                 Countries was developed as a first step to decide on the interest of launching a
OREG 2008 Spring Symposium
                                                                                 new Annex on resource assessment for the various ocean energy sources.
Q u e b e c C i t y, Q u e b e c , C a n a d a , A p r i l 2 1 - 2 2 , 2 0 0 8

                                                                                 The report begins with a presentation of the wave climate and wave energy
INORE 2nd Symposium on Offshore Renewable Energy
                                                                                 parameters and distributions that are used in the description of sea states and in
Edinburg, Scotland, May 4 - 8, 2008
                                                                                 wave energy resource characterization. Some of these parameters are common
                                                                                 to sea waves description having in view climatology and other utilisations of the
All Energy '08
                                                                                 oceans (e.g. navigation, coastal protection, design of ships and offshore structures)
May 21 - 22, Aberdeen, Scotland
                                                                                 while others are additionally required for designing wave energy converters and
AWATEA 2nd Marine Engineering Conference                                         predicting power production.
Te Pape, New Zealand, May 29, 2008
                                                                                 After, an overview of the various wave data sources is made, which includes in
MAREE 2008                                                                       situ and remote sensed wave measurements, and results of wind-wave numerical
International Scientific Meeting Marine Renewable Energy                         models. In situ and satellite-based sensor types are reviewed. However one can
and the Environment                                                              say that the most important source of wave information is numerical wind-wave
Royal Institution of Great Britain, London,                                      models that produce wave energy density spectra on the nodes of a grid covering
June 16 - 17, 2008                                                               the ocean. The relevant wind-wave models that are implemented in the routine
                                                                                 operation of institutes and centers worldwide are presented. Details of the availability
OMAE 2008                                                                        of wave results produced by the models implemented globally or regionally are
Estoril, Portugal, June 15 - 20, 2008                                            described and the most common uses of the various data types are analyzed.
                                                                                 Several wave energy atlases and databases have been compiled that are reviewed
ISOPE-2008                                                                       in the report.
Vancouver, British Columbia, Canada, July 6 - 11, 2008
                                                                                 Finally, a country-by-country review of wave data, namely the national in situ
WREC - World Renewable Energy Congress X and                                     measurement programmes and the available wind-wave model results is presented.
                                                                                 A detailed analysis including the identification of the measuring devices, their
Glasgow, Scotland, UK, 19-25 July 2008
                                                                                 location and water-depth, data type and availability is made, showing the significant
                                                                                 d i ff e r e n c e s a m o n g c o u n t r y p r o g r a m m e s a n d d a ta d i s t r i b u t i o n p o l i c i e s .

Second International Conference on Ocean
                                                                                   Executive Committe Chair                                     ANNEX II: Development of recommended
Energy (ICOE)
                                                                                                                                                practices for testing and evaluating OES
Targeting successful deployment of commercially viable                             Gouri Bhuyan
ocean energy systems worldwide                                                                                                                  Contact: Kim Nielsen (
15, 16 and 17 October 2008                                                         Executive Secretary                                          ANNEX III: Integration of ocean energy plants
Co-organised by EDF and IFREMER
                                                                                   Ana Brito e Melo                                             into electrical grids
                                                                                   (                                 Powertech Labs
This conference aims to bring together marine energy                                                                                            Contact: Gouri Bhuyan
stakeholders, end-users, supply chain, scientists and sea                          Operating Agents                                             (

users as well as institutional and political representatives.                      ANNEX I: Review, exchange and
It concerns all forms of renewable marine energy - wave,                           dissemination of information on OES
current, tide, marine thermal energy, salinity gradient, floating                  INETI
                                                                                   Contact: Teresa Pontes
offshore wind and algal biomass.

The object is to attract participants from industry through a
conference focusing on "innovation to industrialisation". Key
                                                                                 How to participate in the IEA-OES
areas of research and development, such as understanding
                                                                                 If your country has not signed the Implementing Agreement, contact the Executive
environmental impact, will however remain central to the
                                                                                 Committee Chairperson who will provide you with information on how to proceed.If
agenda. The aim is also to include regional, national and
                                                                                 your country has signed the Implementing Agreement contact the Executive
European contexts.
                                                                                 Committee member from your country or the Operating Agent of the Task(s) you
                                                                                 are interested in.
ICOE website :
SeaTechWeek website :   
                                                                                 The IEA-OES Website:

                                                                                     Publication        IEA-OES Executive Committee                               Acting Editor        IEA-OES
Michel Paillard (Ifremer)                Cyrille Abonnel (EDF R&D)
                                                                                      Design            INETI - DER                                               Circulation         700 copies    
tel: +33 2 98 22 41 25                   tel: +33 1 30 87 78 81                       Printing         CLIO - Artes Gráficas                                      ISBN                1645-7811

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