In response to Norman Newton’s letter on the true cost of wind power, he doesn’t have to look far to realise that there is a large body of work which has looked at the CO2 emissions and energy balance of on-shore and off-shore wind turbines. The field of study, Life Cycle Assessment, is developing rapidly and has its own set of standards and protocols.
For wind energy, it has been shown that the energy payback period for both onshore and offshore wind turbines, including transmission, is around 7 months. The offshore turbines have higher material consumption for foundation and transmission but the wind speed is higher offshore and so the results turn out to be very similar.
The global warming potential of 1kWh of wind generated electricity is approximately one percent (i.e. one hundredth)) of the global warming potential of the typical mix of electricity production.
So on these basic environmental measures, the total of more than 250 GW of wind energy installed in the world is a good thing!
Dr Garry Jenkins, Bywell, Stocksfield, Northumberland