Professor Bebbington might care to clarify her letter about wind and back-up (May 7).
All intermittent sources of renewable energy such as wind require reliable fossil fuel, nuclear or biomass standby. The capital and maintenance costs of this are high and ensure wind power will remain costly.
The more serious problem with renewables like wind is the low density of energy collection. To provide electricity equivalent on average to the Cockenzie power station on the Forth would require 1500×100 metre turbines covering 50 square miles. But if turbines are kept at a recommended minimum of 900 metres from any house then probably the whole of the Lothians would be swathed in turbines. Even then, Cockenzie could not be closed but would have to be expensively maintained to provide electricity when the wind does not blow or to smooth out its inevitable fluctuations.
Wind power can be a useful adjunct to supply but unspoiled countryside is at a premium in our crowded island, so I prefer wind farms well offshore. The Sustainable Development Committee may not have industrial representation but membership of environmentalist organisations will always raise questions of bias and lack of balance in reports and letters.
Anthony Trewavas FRS, FRSE, Professor in Plant Biochemistry, Institute of Molecular Plant Science, Mayfield Road, Edinburgh.
15 May 2008