Dear Editor,
CSP AND THE USE OF WATER
It is true that the pioneering CSP plants in California use quite a lot of water ('Solar power – the hidden threat to water supplies', 18 August) but as your article makes clear, dry cooling is a well-established option and the additional cost is not large. It is not necessary to use large amounts of water for cleaning mirrors. Some dampness may be helpful but other options include the use of brushes or compressed air, and treatments for the surfaces of mirrors that reduce the need for cleaning.
CSP is an attractive option in desert regions because it is still cheaper than PV and, with heat storage and backup sources of heat, it can provide power on demand, day and night. But as the price of PV falls, it is likely to be more widely used. The potential of wind power in desert regions has been recognised for some time.
Sincerely,
Dr Gerry Wolff PhD CEng
Coordinator of Desertec-UK
+44 (0) 1248 712962,
