Draft NZ Energy Strategy.
Submission by DH Tucker, Consulting Engineer, Dunedin.
1. Introduction I am a consulting Engineer with over 40 years experience in the
infrastructure and energy sectors. I have worked with geothermal energy, mini-hydro,
wind power, biogas, solar, electric cars and in other related areas. In recent years I have
taken a particular interest in renewable energy, and in 2006 I attended the World Bio-
Energy conference in Sweden, two similar UK conferences, and visited several sites. My
present activities include a Landfill Gas project, and two wind power projects.
2. Background New Zealand has a unique energy basis, so solutions to problems and future
policies need to be essentially fitted to New Zealand, and not just copied from other
country’s solutions. The key elements are :
A small population (just over 4 million people) remote from world centers.
General interest in international factors, e.g. green house gas problems and peak oil.
A small and mainly unsubsidised economy.
A long narrow country surrounded by seas with a temperate climate.
A wide range of potential renewable energy sources.
Traditionally hydro electricity generation, plus backup thermal generation.
3. Energy Profile New Zealand’s primary energy supply profile is essentially :
2005 (NZ Energy data File) 2030 (with reduced greenhouse emissions)
35% Oil (imported) 28% Change = -7%
20% Gas (local) 14% -6%
13% Coal 3% -10%
12% Hydro 15% +3%
12% Geothermal 18% +6%
5% Biomass 5% n.c.
3% Oil (local) 4% +1%
0.3% Wind. 5% +5%
0% Biofuels 7% +7%
0% Wave & Tidal 1% +1%
These changes, over 25 years, suggest a significant move away from fossil fuels and the
development of mainly renewable energy methods to replace them, and cope with the normal
energy demand growth. However policies must be put in place to achieve these changes, which
I believe should be regarded as a minimum.
4. Targets As EU and other countries are doing, I believe New Zealand should set in place
significant targets, stepwise increasing until a longer term target is achieved. Thus :
Electricity Generation to be totally from renewable resources by 2020.
Transport fuels to be 20% from renewable resources by 2020.
Are these achievable? I believe so –there is significant electricity generation from geothermal
and wind already being employed, and these resources can be further developed to meet the
larger targets. Hydro has problems of public sensitivity to environmental changes to overcome,
and the wave/tidal energy resource is only at a very early development stage overseas.
Transport fuels present another problem as they are almost entirely based on imported oil, plus
natural gas from the nearly exhausted Maui field. But Brazil provides nearly 70% of its
transport fuels from biomass converted to ethanol, and New Zealand should be able to do
likewise. Returning to ship and rail transport between main centers should also be developed.
A major change in our people’s way of life is unavoidable in the next decade or so if planned
changes do not counteract the greenhouse gas emissions and peak oil problems now upon us. In
my experience only a world war, or a fundamental shift in global economies can cause such a
change. Far better to build in a stepwise change by means of fundamental policies and targets,
with penalties by sector if they are not achieved.
5. Potential Renewable Energy Resources and Greenhouse Gases Reduction.
Agriculture : Livestock farming is New Zealand’s largest industry, and due to
methane emissions from grazing animals it also adds significantly to our greenhouse
gas emissions problem. The simplest, transparent method to resolve this problem, on a
polluter pays basis, is to have the farming community take up farm forestry again, and
require each farm to plant or retain on its property enough trees to match the potential
for methane generation based on the farm’s stock units valuation. Farm forestry is
presently less profitable than dairy or other forms of farm production, thus tax credits
would appear to be the logical means of encouraging this policy. Targets should be
set, and if they are not achieved, penalties applied.
Forestry : The forestry sector has decreased in recent years, due to profitability falling
below that for other land use activities. Investment in forestry projects must be
encouraged, and there are many ways to do this. Also, particularly in Europe, forest
wastes are used extensively to provide biomass fuels, for conversion to pellets for
household heating, and for conversion to gaseous or liquid fuels.
Biogas : New Zealand probably leads the world in pasture management and grassland
development. This expertise can be utilised to provide the raw material to gradually
replace our present reliance on imported oil, with its security of supply risk and the
threat of escalating oil prices due to the imminence of peak oil.
The 2006 Bio-Energy conference featured a number of processes, some in full scale
production, and others at the prototype stage, converting grasses to energy and other
products. For example, Izes gGmbH in Saarbruken (Germany) have developed a
process to convert grass into energy, fertilizer and insulation board. At the University
of Minnesota mixed grasses are the raw material for biofuel production, reportedly
yielding more energy per hectare than the traditional corn and soya. In addition the
overall process is carbon negative – it absorbs more carbon than it releases.
Biogas is essentially methane with a proportion of carbon dioxide, the ratio depending
on the fuel source and the process. Starting materials include sewage sludge, grasses,
manure, agricultural and food wastes, and Landfill Gas. Most mixtures are from
anaerobic bacterial digestion, which can be adjusted to become the equivalent of
CNG. New Zealand has ample experience in the distribution and use of CNG, and for
the conversion of petrol and diesel engines to CNG. Surely this process is ideal for
New Zealand, and should be aggressively investigated and developed.
In addition, alternative bacterial processes from the same feedstocks can be used to
produce biohydrogen, which is likely to become a significant fuel source in the future.
Liquid Biofuels : Liquid fuels are essentially for the transport industry, and are thus of
primary importance to New Zealand. New Zealand can benefit from the extensive
research, and many trial production units found overseas. These works are mainly for
bioethanol and biodiesel, both of which can be utilised by the present vehicle fleets,
with only inexpensive minor modifications in some instances. In addition, biofuels are
generally much cleaner, and contribute far less greenhouse gases than do their
petroleum based equivalents.
Bioethanol is extensively produced and utilised in Brazil (from sugar cane) and in the
USA (from food crop residues). Other starting materials are sugar beet, corn, barley,
wheat and woody biomass. New Zealand has a strong agricultural base and could
readily source suitable materials, if there was a processing facility, and the crop prices
were profitable. Research is needed to establish which crop is the most efficient for
fuel production, on a whole of use basis, so that production facilities and crop farming
can be initiated. Lignocellulose (e.g. waste wood) biomass should also be considered
as its use for ethanol production would reduce pressure on food crops.
Biodiesel is already produced from tallow on a small scale in New Zealand, and this
production should be ramped up instead of selling tallow overseas for less than the
cost of imported oil for the transport sector. Other starting materials are rape seed oil,
sunflower oil or even used cooking oil. Rape used to be grown extensively for its oil,
with the rest of the crop suitable for fodder – this industry should be re-started.
Hydro Generation : major hydro systems, causing massive changes to catchments and
rivers are no longer tenable for environmental reasons. However smaller systems,
such as mini hydro and micro hydro are feasible, and should be developed. The
present resource consent process is a serious hurdle for many such schemes. I know of
one such, a very clever invention using recycled materials which has been halted due
to the requirement of four (4) resource consents before even a trial of the prototype
can be undertaken. The expense and time lost to pursue such a project is just not
sensible. The same applies to activities such as establishing wind patterns for possible
wind turbine sites, and trial landfill gas activities which previously had been
consented on a commercial scale.
Nuclear : Another proven energy generation technology, but politically unacceptable
in this country at present. There too many negative or unsolved problems with nuclear
energy for even long term consideration. Nuclear Waste disposal obviously, and
safety, but also economies of size mean at least a 1000 MW size unit, requiring also a
backup generation facility of similar size for the outage periods for maintenance etc. A
second, standby nuclear power station? Not for New Zealand in the foreseeable future.
Photo Voltaic (PV) : Conversion of Solar Energy into DC electricity is a proven
technology, but except for remote applications such as repeater stations, MW links etc
I doubt if the capital cost can be justified. This situation has been accentuated by the
German government subsidizing PV at household level such that the demand exceeds
the supply internationally with consequent price increases as production is expanded.
Perhaps the following stage of over production will lead to massive price falls, so that
PV can become a major generator in true sun belt countries. But not NZ as yet.
Solar Water Heating : Domestic water heating is a major user of electricity in New
Zealand, and thus solar is a useful contender provided there is a heat sink (HW
storage) to accept the energy when it is available. Similarly Solar can be used for
space heating using in-slab hydronic floor heating systems. The system usually comes
with a mains powered backup heating element. This must be controlled so that the
solar system has first priority over every 24 hour period. It remains to be seen how the
present Government scheme to assist solar HW development progresses.
Tidal Energy : I believe the use of tidal flows for electricity generation will become a
vital element in New Zealand’s generation development. Cook Strait has enormous
potential, close to Wellington, and the predictable slack tide periods can be balanced
by tidal generation from Foveaux strait and the Kaipara harbour or other Northern
estuaries. Tidal technology is very new, with major full scale trials only now starting
in the Orkneys north of Scotland. There are potentially enormous problems with
generation under the sea, e.g. corrosion, pressure and the undersea environment.
Whales and other large sea creatures must also be considered. New Zealand is too far
away from centers of marine engineering and too small a country to fund development
activities of this type, thus I believe NZ should await the overseas development of
proven tidal generation units before investing in them – probably 10 years hence.
Wave Energy : Similar to Tidal Energy, wave energy is at the very early stages of
development in Europe, and again investing in this new energy process should await
overseas developments. In addition I am not keen on the visual effects on our pristine
coastal environment of floating devices making use of the waves that batter our
Wind Energy : Power generation from Wind has been suggested as the likely saviour
for New Zealand’s generation shortage over the next decade. Generation from wind
energy can be developed in increments and costs are now comparable with alternative
generation costs. The main problems are its intermittent nature, consequent difficulties
in integration into the distribution system, and the environmental concerns of some
sectors of the public. Wind increases at higher altitudes, so policies should minimize
high country restrictions to wind farms. But these problems are surmountable.
The intermittent availability of wind generation can be resolved by having wind farms
at several locations in the country, as each area has a different wind pattern. Also
integration with our large hydro generation capacity will allow a much more efficient
use of both generation resources as hydro power can be stored when the wind blows.
The environmental lobby is small but vociferous, and under the NZ Resource Consent
Process must be heard and evaluated. Overseas studies have shown that many anti-
wind farm advocates reverse their position within a year or so of the establishment of
a wind farm, the stately and mesmerizing effects of a group of wind turbines
becoming a local feature. Noise is seldom a problem with modern designs, and the
effects on bird life have been established as minimal outside of migratory flight paths.
I believe that a mix of large (several hundred MW) and smaller (0.5 to 50MW) wind
farms can meet all requirements, particularly if the smaller wind farms use smaller
turbines, and are located in less prominent areas. The Windflow 500 turbine,
developed and almost entirely manufactured in New Zealand should be used
extensively, and I am concerned that the major generators, and the Government have
not assisted in its development. Major wind farm developers should be required to
include a small number of Windflow 500 units, so that operating experience and
manufacturing development can be extended in New Zealand.
Distributed Generation : New Zealand generates almost all of its electrical needs in
major generation stations, hydro, thermal and geothermal. These are usually
continuously operated as except for gas fired turbines, start up and shut down times
are excessive and costly. Thus the NZ power systems do not at present include or
allow adequately for intermittent power generation, particularly on a small scale.
However there are many sites where small scale generation could meet the local need
most of the time, and export power at other times – but it is seldom economic to do so
due to the present power system operations, operators and tariffs.
I believe it would benefit the power system as a whole if distributed power schemes
were encouraged by requiring the major generators and purchasers of electricity to
always purchase these smaller quantities at a fixed and reasonably generous rate, e.g.
the marginal cost of additional power generation facilities.
5. Conclusions :
The following 12 conclusions summarise my submission :
Policies and Targets must emphasize the shift to Renewable Energy programs.
Total Electricity generation from renewable resources - Target by 2020.
20% of all Transport Fuels from renewable resources - Target by 2020.
Farms to develop farm forestry to compensate for livestock methane emissions.
Research on Grass conversion to Fuels to be aggressively developed.
CNG equivalents from various resources to be developed for vehicles fuel1.
Research on the most efficient crops for conversion to Fuels to be undertaken.
Resource Consent process to be minimized for small and experimental projects.
Solar water heating to be developed for space heating as well as domestic HW.
Overseas Tidal Energy development programs to be closely monitored.
Wind Turbine development in NZ to be aggressively supported.
Distributed Energy generation projects to be developed and supported.
D H Tucker March 2007.