United States

United States

Wind index advantage in Europe

Google Translate

Accurate predictions of wind plant production in North America are hindered by the lack of a comprehensive and universally respected index of wind strengths built up over many years, say experts. The gap between predicted and actual production in America is almost twice the size of that in Europe (main story), where wind indices have been developed since the 1980s to provide a baseline for how hard the wind is likely to blow in any given area during the assumed 20-year life of a wind plant. Wind indices specially developed by the industry are available in Denmark, Germany, the Netherlands, Sweden and the UK and are calculated from the energy production reports of strategically selected wind turbines (Windpower Monthly, January 2006).

Everyone has data they rely on in North America, says Andrew Garrad, head of international wind consultancy Garrad Hassan. "But I think to call it an index is to give it too much credibility." In identifying the performance gap, Garrad Hassan compared all the US wind speed data in 2007 to the best observations taken over 15 years.

The analysis revealed that winds in 2007 were about the same as the 15-year average in some areas, but poorer in others. West Texas, where thousands of megawatt of wind plant operate, saw the worst wind in 15 years. Garrad says that this is one reason for the observed shortfall of energy produced by wind turbines in the American fleet in 2007.

Robust wind indices for different regions of America that most companies can rely on would greatly help in the prediction of wind farm production. But that is a tall order to accomplish for such a large country, admits Garrad. "We have been trying to put one together but because it's such a big place, it's very difficult to do, and I would say that were quite a long way off from having such an index in a reliable form for the US," he says.

Have you registered with us yet?

Register now to enjoy more articles
and free email bulletins.

Sign up now
Already registered?
Sign in