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The potential of renewables

There is no question that renewables can meet world demands for energy (not just electricity), and anticipated future demands (see below). Here is some of the evidence:
  • A network of land-based 2.5-megawatt (MW) turbines restricted to nonforested, ice-free, nonurban areas operating at as little as 20% of their rated capacity could supply more than 40 times current worldwide consumption of electricity and more than 5 times total global use of energy in all forms. There is additional potential in offshore wind farms. See Global potential for wind-generated electricity (PDF, 1.9 MB, Xi Lua, Michael B. McElroya, and Juha Kiviluomac, Proceedings of the National Academy of Sciences of the United States of America, June 22, 2009, doi: 10.1073/pnas.0904101106). 
  • The "economically competitive potential" of wind power in Europe is 3 times projected demand for electricity in 2020 and 7 times projected demand in 2030. Offshore wind power alone could meet between 60% and 70% of projected demand for electricity in 2020 and about 80% of projected demand in 2030. See Europe's onshore and offshore wind energy potential (PDF, 3.5 MB, European Environment Agency, 2009). The UK is one of the windiest parts of Europe.
  • Renewable energy technologies can provide 100 percent of the world’s energy (not just electricity) and it is technically feasible to make the transition by 2030. See "A path to sustainable energy by 2030" (PDF, 1.4 MB), an article by Mark Z. Jacobson and Mark A. Delucchi in the November 2009 issue of Scientific American. This article reviews research showing that there are more than enough renewable sources of power to meet all of the world’s energy needs, not just electricity. In the scenario described in the Scientific American article, wind supplies 51 percent of the demand worldwide, provided by 3.8 million large wind turbines (each rated at five megawatts). Although that quantity may sound enormous, it is interesting to note that the world manufactures 73 million cars and light trucks every year. An interesting conclusion of this research is that, because there would be much less wastage of energy in a renewables scenario, total world demand for power in 2030 would be 11.5 terawatts, using renewables, compared with 16.9 terawatts if we were to stick with conventional sources of energy. See also the interactive presentation about this research: Powering a green planet: sustainable energy, made interactive (Scientific American, November 2009) and Review of solutions to global warming, air pollution, and energy security with Supplementary information.
  • The variability of sources such as wind power is much less of an issue than is sometimes suggested, as described in Managing Variability (PDF, 402 KB, a report by independent consultant David Milborrow commissioned by Greenpeace, WWF, RSPB, Friends of the Earth, July 2009). Electricity transmission networks in the UK are already designed to cope with variability arising from the failure of power stations and from variations in consumer demand, and that, for a small additional cost, wind power could provide up to 40% of the UK's electricity. Further increases in the level of wind penetration are feasible and do not rely on the introduction of new technology. See also Matching variable electricity supplies with variable demands.
  • Photovoltaics (PV) could generate about 266 TWh/yr in the UK - about 66% of the UK's present electricity demand. See Renewable energy and combined heat and power resources in the UK (PDF, 600KB, Tyndall Centre, 2002). PV is quick and simple to install.
  • Using concentrating solar power (CSP), less than 1% of the world's deserts could produce as much electricity as the world is using. Less than 5% of the world's deserts could produce electricity equivalent to the world's total energy demand (see The Desertec Foundation and Desertec-UK). These calculations, which are quite conservative, are based on research from the German Aerospace Centre (DLR). Although it would be possible to obtain all the world's energy from deserts, there are several reasons why Europe and the UK (and other regions and countries) should use a variety of renewable sources of power, as described in the TRANS-CSP report from the DLR which may be downloaded via links from http://www.trec-uk.org.uk/reports.htm.
  • The government's own plans for the growth in renewables and energy conservation can ensure adequate generating capacity in the UK until at least the mid 2020s. See Implications of the UK meeting its 2020 renewable energy target (PDF, 734 KB, Pöyry Energy (Oxford) Ltd for WWF-UK and Greenpeace-UK, August 2008).
  • An economic model conducted for the New Scientist suggests that radical cuts to the UK's emissions will cause barely noticeable increases in the price of food, drink and most other goods by 2050. See Low-carbon future: we can afford to go green (New Scientist, 2009-12-02).
  • There are several other reports on how to decarbonise the world's economies via renewables and the conservation of energy, without using nuclear power. A more comprehensive list, with notes and download links, is on http://www.mng.org.uk/gh/scenarios.htm.

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, with other techniques for balancing the grid, 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, residual needs for the heating of buildings should be small.

News reports

News reports relating the potential of renewables are marked 'R' on our News page.