Monday, November 09, 2009

The potential of renewables

Thanks to Gerry Wolff for this extremely valuable resource.

There is no question that renewables can meet the UK's present and anticipated future demands for electricity, even allowing for future uses of electricity for such things as space heating (eg using electrically-driven heat pumps) and the electrification of transport by road and rail -- more below. Here is some of the evidence:

Future developments

Electrification of road and rail transport in the UK would add to the UK's demand for electricity but not as much as one might think:
  • In terms of energy, about 50% more electricity would be needed (see Appendix 8 of "Energy UK" (PDF, 378 KB, The reason it is not more is that electric motors are very much more efficient than internal combustion engines. Much of the energy that we are using now for overland transport is simply wasted.
  • In practice, the additional amount of generating capacity that will be required is likely to be less than 50%. This is for two reasons:
    • It is likely that much of the charging of electric vehicles will be done at night when there is likely to be a lot of spare capacity from sources such as wind power. To that extent, it does not add to the generating capacity that would be required.
    • The electrification of road transport will facilitate the introduction of grid-to-vehicle technologies allowing two-way flows of electricity between vehicles that are on charge and the transmission grid. This will help to keep demands for electricity in balance with supplies, thus helping to minimise the amount of spare capacity that is required.
It seems likely that, in the future, there will be increasing use of electrically-driven heat pumps to provide space heating in buildings. But, with good insulation of buildings and the use of technologies such as inter-seasonal heat transfer (see, for example,, residual needs for the heating of buildings could turn out to be small.

Energy costs

Accurate information is critically important in any kind of cost-benefit analysis. In weighing up the pros and cons of various sources of power, it is important to take account of the fact that energy markets are distorted:
  • In a report published in 2004 ( the New Economics Foundation made a conservative estimate that worldwide subsidies for fossil fuels amounted to about $235bn a year—and there seems not to have been much change since then.
  • The continued existence of subsidies for oil, gas and coal is confirmed by recent reports that the G20 countries intend to remove them (see, for example,
  • Contrary to what is suggested by the nuclear industry, and widely believed, nuclear power is heavily subsidised. The subsidies are described in Nuclear Subsidies (PDF, 167 KB,, a report from the Energy Fair group. If just one of those subsidies was to be removed—limitations on liabilities—the cost of nuclear power would rise to about 41 US cents per kWh, a level that would make it deeply unattractive to investors.
  • There is still no global cap on emissions of CO2 and schemes such as the EU ETS are not working properly. For those kinds of reasons, the price of CO2 emissions is far too low.
Removal of these distortions would transform our perception of what is or is not 'economic'. It is likely that most renewable sources of electricity would be seen to be cheaper than electricity from fossil fuels or nuclear power.

Removal of these distortions would mean that subsidies for some renewable sources of power could be reduced or removed altogether (see

There would probably be a need to retain subsidies for renewables that have not yet reached the bottom of their cost-reduction curves.

In some cases there may be special reasons for providing support. For example, if the majority of people feel that onshore wind farms spoil the landscape (and that is by no means clear) there may be a case for providing a subsidy to cover the extra cost of putting wind turbines out at sea.

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