COUNCILLOR Jane Waterhouse?s enthusiasm for ?an army of wind turbines? suggests that she, as have many others, has overlooked a number of points that have been concealed from the public by those intent on promoting the technology.
1: Wind turbines suffer from instability of output and outright unavailability because they depend on the highly variable wind. Output to the grid has to be maintained between very tight voltage and frequency limits, or serious damage can occur to plant and indeed electricity customers? equipment. The bigger the percentage of the grid?s input from windpower, the greater the risk of partial or complete failure of supply.
2: In view of this, the Irish government last year stopped all new applications for windfarms in Ireland, where the availability of wind is somewhat greater than in Devon. The reasons were the threat to the security and safety of supply.
3: A consequence of the need to secure supply irrespective of wind conditions is that every wind installation needs to be backed up by stand-by generation from conventional sources.
No one is prepared to carry reserve generation to replace lack of wind at anything like an economic rate, because it is technically and environmentally inefficient and expensive to hold plant in an ?understudy? role.
4: To avoid turbulent airflow downwind of a turbine, which reduces efficiency and can induce structural flexing, hastening fatigue failure, turbines need to be separated by at least ten times the diameter of the rotors. This means in order to replace one typical conventional power station, an area up to 100 square miles would have to be covered with turbines.
5: The Royal Academy of Engineering this year published a study of the real costs of nuclear, fossil (combined cycle) and wind generation, using the latest technology. Total costs per kilowatt-hour including decommissioning were combined cycle 2.2 pence, nuclear 2.3 pence, and wind power (including standby replacement) 5.4 pence. (offshore wind power is nearly 2p per Kwh greater).
If you want to see what ?an army of turbines? really looks like, go to the Spanish Costa de Luz and be appalled. Rank upon rank of turbines many stopped and some dismounted for unaffordable repairs, defile an area not unlike Dartmoor. Just be warned.
Geoffrey M Stowell
The Down
Bere Alston