There was quite a bit of ballyhoo around the anti-wind network a few weeks ago concerning a study funded by the misnamed Renewable Energy Foundation (a British anti-wind group). The study suggested there was an issue with wind turbine performance over time that would have a negative impact on wind energy's economics. We cross-posted the European Wind Energy Association's response, which described the wind turbine life span study as "propaganda," here.
Now a new analysis from energy economics and technical expert David Milborrow, a longtime contributor to the publication Windpower Monthly, has found that the output of older wind farms in Denmark, where some of the first wind farms in Europe (both land-based and offshore) were built, has remained strong. Quoting Mr. Milborrow's conclusion:
"REF's report suggests that the capacity factor of Danish onshore wind farms falls off by four percentage points over 15 years, whereas an analysis of the capacity factor of 20-year-old turbines suggests that the degradation only amounts to about 0.7 percentage points over 20 years. REF says performance of offshore wind turbines falls by 30 percentage points over ten years, from 40% to 10% approximately, whereas an analysis of the data from the longest-running Danish offshore wind farms reveals that two of them have increased in performance, and the third has only recorded a 1.5 percentage-point drop in capacity factor, extrapolated to 20 years. It is not clear what accounts for the discrepancy between the analysis laid out above and the REF work."
Concerning the Renewable Energy Foundation, EWEA's previous response noted, "The Renewable Energy Foundation claims to be 'a registered charity promoting sustainable development for the benefit of the public by means of energy conservation and the use of renewable energy' although [its] website is made up almost exclusively of criticism of wind energy."
Fact check: Marshall Institute attacks wind power, ignores facts, January 15, 2013
Fact check: Study on turbine lifespan 'just more anti-wind propaganda', December 24, 2012
Wind technology advancing rapidly, challenges remain, June 4, 2012
Fact check: American Enterprise Institute FAIL on study of wind costs, February 29, 2012
Wind power increasingly competitive and productive, new reports find, November 10, 2011