While we were all reading about climate sensitivity yesterday, the Renewable Energy Foundation published a devastating report by Gordon Hughes on depreciation of wind turbines.
The results show that after allowing for variations in wind speed and site characteristics the average load factor of wind farms declines substantially as they get older, probably due to wear and tear. By 10 years of age the contribution of an average UK wind farm to meeting electricity demand has declined by a third.
This decline in performance means that it is rarely economic to operate wind farms for more than 12 to 15 years. After this period they must be replaced with new machines, a finding that has profound consequences for investors and government alike.
The report is here.
If the lifetime of a wind turbine is 15 years rather than 25, that presumably means that the electricity it generates is going to be much, much more expensive. Douglas Carswell MP called the government's energy bill a disaster. He wasn't joking was he?