Select Committee on Environment, Food and Rural Affairs Written Evidence

Memorandum submitted by Professor Peter F Smith (U02)



  On the demand side, there should be a radically new strategy for reducing CO2 due to buildings and transport with the introduction of carbon budgets. On the supply side the UK is well down the EU league table as regards installation of renewable energy technologies. Britain is especially fortunate in having extensive marine resources offering multi-gigawatt power. However, a strictly market approach will not deliver long life, high energy density but high capital cost technologies. Research into renewable technologies is considerably underfunded compared with other EU states. The potential market opportunities for low to zero carbon technologies should persuade the Government to invest more ambitiously in R & D in this area. As regards transport, increased subsidies should be offered on hybrid vehicles as the range of such models is enlarged. Provision of incentives for the production of biofuels and the conversion of existing vehicles to these fuels should be a priority matter to reduce low level pollution and CO2 emissions. In terms of global policy, there should be an emphasis on providing access to off-grid electricity to least developed countries.


  Buildings are still indirectly responsible for a major share of the UK's CO2 emissions. Research should be commissioned into the logistics of replacing Part L of the Building Regulations with a carbon budget system for all buildings. This would have the advantage of bringing all buildings into the carbon reduction process whilst avoiding the social penalties of significantly higher energy prices. It would also pave the way for a system of carbon trading with a premium on the base price of carbon credits.

  1.1  The system could also be applied to vehicles (see below).


  In terms of the expansion of renewable energy the UK has no cause for complacency. This is shown by the European Environment Agency 2004 in a comparison between 25 EU states of their commitment to renewable energy. The UK is fourth from bottom of states that rise above the base line (Figure 1).

Figure 1

  2.1  There is need for vigorous exploitation of the natural assets enjoyed by the UK for the production of renewable electricity. The outstanding resource is the marine environment. A steep increase in the installation of renewable technologies will not be achieved if reliance is placed on market forces, especially for long life, low running cost by high capital cost technologies that deliver gigawatt power like tidal energy. It is not enough for the Government to fund demonstration schemes and then rely on the private sector to run with them. Marine resources offer the greatest opportunity for base load power generation.


Estuary tidal power:

  In 1994 the Government decided to abandon further research into tidal barrages for reasons ranging from the economic to the ecological. Since then the position has changed. Rivers are much less polluted and the risk of catastrophic flooding in the next decades has risen appreciably making it appropriate to reappraise the position.

  3.1  Tidal barrages: are appropriate where flood protection is a major factor for example for the Thames Gateway development Figure 2. A barrage in this position could probably meet the electricity needs of the projected urban expansion of London especially if associated with tidal pounds to provide power during slack tidal phases.

  3.2  Tidal fence: technology is an alternative to barrages. Vertical Darrieus rotors are supported within an open concrete structure Figure 3. The system has a high energy density without causing problems for the inter-tidal zones. It is appropriate for estuaries, bays and channels, eg Severn estuary, Morecambe Bay, Pentland Firth.

  3.3  Tidal currents: The UK has over 40 coastal sites appropriate for capturing tidal stream energy from underwater horizontal axis turbines (tidal mills). We should progress from demonstration schemes to full scale exploitation.

  3.4  Tidal impoundment: This is a proven technology as demonstrated by the project off the coast of North Wales with a capacity of 432MW. There are many suitable sites for this relatively low cost, reliable and unobtrusive form of tidal power.

  3.5  Wave power: The "limpet" project on the Isle of Islay has proved the effectiveness of coastal oscillating water column technology. Sites should be investigated with a view to expanding this moderate cost technology.

  3.5.1  The "Pelamis" or "power snake" offshore technology has considerable potential, especially in multiple arrays as wave energy farms.

  3.5.2  The wave elevator system or "Tapchan" as demonstrated in Norway consists of a narrowing channel which amplifies wave height lifting sea water about 4m into a reservoir. It then has sufficient height to operate as a conventional hydro-electric plant, in this case generating 370 kW. There could be suitable sites in Scotland and the South West.

  3.6  Offshore wind: If wind is to make a significant contribution to renewable energy targets the focus should be on offshore machines because of their better load factor than land based turbines and because they circumvent the delays associated with the planning process.


  The government should set ambitious targets for energy from:

  4.1  Rapid rotation crops for use in former coal fired power stations and production of biogas.

  4.2  Biogas from waste including anaerobic conversion of sewage and farm slurry.

  4.3  Energy crops for ethanol and biodiesel.

  4.4  Photovoltaics (PVs): Compared with some other EU countries and Japan the UK has a poor record in exploiting solar power. This is because PVs are uneconomic in the current market situation. Solar energy has the greatest potential of all renewables and much greater research funding should be directed towards this technology.

  4.4.1  The lesson from Germany is that subsidies are necessary to pump prime the market and thereby to gain from economies of scale. The German Photovoltaic Preliminary Act 2004 paved the way for the revised Renewable Energy Act which provides for a feed-in tariff of around 50 Eurocents per kWh for roof and façade PVs on domestic as well as commercial properties. The anticipated installed capacity up to the end of 2004 is 580MW. German manufacturers cannot keep pace with demand which is why the Welsh PV plant is exporting almost all its capacity to Germany.

  4.4.2  The first step to boost the UK market would be to provide net metering for domestic/small scale PV installations and micro-wind with matching feed-in and buy-in rates.

  4.5  There will be serious implications for the grid when over 20% of electricity comes from distributed and small-scale generation. Planning for this outcome should now be well under way.


  Much of this gas still escapes into the atmosphere. Methane is 27 times more potent as a greenhouse gas than CO2 therefore it is important to burn it for energy rather than let it escape to the air.


  The UK is still only on the threshold of exploiting this resource as a means of avoiding CO2 emissions. It can be used for either diurnal or seasonal storage of warmth. In 1999 the EU Soltherm Europe Initiative was launched with the aim of installing 15 million m2 of solar thermal collectors by 2004.

  6.1  Germany responded with its Solarthermie 2,000 research project with programmes like the housing project at Friedrichshafn with 5,600m2 solar collectors on the roofs of eight apartment blocks. A 12,000m3 underground heat store collects summer warmth for distribution in winter. This amounts to 1,915 MWh/yr. A scheme at Neckarsulm has a collector area of 27,000m2 to meet a heating demand of 1,663MWh/yr.


  At present ground source heat pumps are marginal in terms of cost effectiveness. However, efforts are underway to increase their coefficience of performance (COP) from three to five or six. Some claim eight will be possible. This will make them attractive for producing space heating with the added benefit or providing cooling in summer.


  Developments in the efficiency of the Stirling engine have made micro-CHP a viable proposition. Particularly hopes rest on the Microgen system in which electricity is produced within a sealed Stirling engine. Assuming a manufacturer can be found to meet the exacting tolerances it should be on the market in 2005 and be competitive on cost with conventional systems with the bonus of producing 1KW of electricity. The attraction of this system will probably depend on the availability of net metering.


  Whilst efforts to persuade motorists to revert to public transport will continue, the probability is that the volume of vehicles will continue to increase even if the fuel price escalator is reinstated. Therefore most effort should be concentrated on persuading car owners to opt for hybrid or alternative fuel vehicles. To do so it will be necessary to provide capital grants to make up the difference between hybrid and conventional vehicles as well as concessions on excise duty. At present the payback time for the price difference is six to seven years assuming 24,000km per year. Honda and Toyota are planning to expand their ranges and Ford, Nissan and General Motors will have hybrids on the market in the near future.

  9.1  Biofuels: probably hold out the best hope for reducing CO2 and other pollutant emissions in this sector for the medium term future.

  9.2  Ethanol is the most widely used biofuel. It is mainly fermented from corn, wheat or barley but also from biomass waste and rapid rotation poplars. It can reduce greenhouse gas emissions in vehicles by 35-46%.

  9.2.1  A 10% ethanol blended fuel is approved by all car manufacturers marketing in the US. Manufacturers are working to produce more flexible fuel vehicles (FFVs) that are able to use E-85 fuel, that is a blend of 85% ethanol and 15% petrol. There are currently over one million FFVs in the US and main manufacturers are increasingly offering FFVs as standard models.

  9.2.2  E-diesel is being developed containing 15% ethanol which reduced particulate emissions by up to 30%. It also reduces sulphur content.

  9.2.3  An important feature of ethanol is that it is easily reformed to hydrogen in a fuel cell. It offers the prospect of facilitating the uptake of fuel cell vehicles in the short to medium term, either reformed in the vehicle or in garages which will offer pure hydrogen at the pumps. The fuel cell offers efficiencies of 40 to 50% compared with the 18% of the average internal combustion engine.

  9.3  Biodiesel:This fuel is refined from soybean, hemp, rape, vegetable oil and animal fat. Fuel grade biodiesel conforms to strict industry standards and can be used as a replacement for conventional diesel or in any proportion. It reduces CO2 emissions by 78% compared with fossil diesel (US Dept of Energy) due to the closed carbon cycle. Emissions harmful to health are dramatically reduced with biodiesel. Its ultimate promise is for "clean" HGVs and locomotives.

  9.4  In the light of these facts the Government needs to do everything possible to encourage the adoption of alternative fuels and the modification of existing vehicles where necessary. One way to do this would be to apply the carbon budget principle to vehicles with year on year reductions in the carbon allowance. A smart card loaded with carbon credits would be issued with the tax disc. Once the allowance was exhausted the only option would be to purchase carbon credits at a punitive price.


  The UK is well down the league table terms of investment in renewables research.

  10.1  Increased investment is required to reduce the cost and raise the efficiency of various fuel cells appropriate to different uses especially domestic scale fuel cells up 5kW.

  10.2  It is a matter if priority to raise the efficiency and reduce the cost of PVs. For example, support research into solar cells which replace the liquid electrolyte with an organic solid and processes that mimic photosynthesis ("biomimcry").

  10.3  To widen the scope for building integrated PVs it is important to accelerate the development of flexible sheet and transparent PVs which will greatly widen the range of their applications.

  10.4  A range of benefits will accrue from the scaling-up of the microbial fuel cell to produce electricity from human waste. This opens up the possibility of extensive electricity production from sewage works.


  The UK should be a full participant in the race to find low energy methods of producing hydrogen so as to be well placed to exploit the market opportunities at the time when hydrogen will be the principal energy carrier for transport. These include:

  11.1  Alternatives to electrolysis for the production of hydrogen need to be investigated eg:

the hydrogen generator fuel cell producing carbon dioxide and hydrogen from ethanol and water;

  11.1.1  Solar hydrogen using light harvesting ceramics to split water to produce hydrogen (University of New South Wales).

  11.1.2  Microbial activity that releases hydrogen from organic compounds such as biomass waste.

  11.1.3  Regenerative fuel cells.


  The viability of hydrogen for vehicles and static fuel cells will depend on the development of safe storage systems. Current developments include:

  12.1  Metal hydrides with the best storage to weight ratio.

  12.2  Capillary storage in super-activated carbon.

  12.3  Carbon nano-tubes.


  The intermittent nature of supply from renewables increases the pressure to find safe, high capacity methods of electricity storage.

  13.1  There is still considerable scope for improvements in battery technology.

  13.2  The ultimate storage technology is from high temperature super-conductivity. According to the Interdisciplinary Research Centre, Cambridge University, there is the prospect by 2020 of storing massive amounts of electricity in a ring a super-conducting cables with no power loss.


  In the short term air travel should carry a surcharge to acknowledge the multiple forms of damage it inflicts on the environment, not least its escalating CO2 emissions. This would have to be an EU wide initiative. A tax would be levied, perhaps as landing charges, on nations that would not comply.

  14.1  In the longer term it is virtually inevitable that hydrogen will be the fuel of the future once memories of the Hindenburg have been erased.


  One of the global problems that can be tackled is to provide access to electricity to the two billion worldwide for whom it is not available. For most this will involve a massive programme of supplying compact solar energy systems and, to a lesser extent, micro-hydro equipment. The challenge suggested by the Electric Power Research Institute in the US is to provide at least 1,000 kWh per year to everyone in the world by 2050, by which time the world population could be 9 to 10 billion.

  15.1  Also essential will be provision of energy crops and the means of refining biofuels for powering agricultural equipment, pumps and generators. As the price of fossil fuels rise, it will become increasingly out of reach for poorer communities and therefore an alternative should begin to be put in place immediately.

  15.2  These will be important actions towards realising the Prime Minister's goal of alleviating poverty in Africa.

  15.3  Finally, it is probably necessary to accept that no further time and effort should be expended on trying to achieve closure of the Kyoto process.

19 September 2004

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