I’m a numbers and evidence kind of guy, so when a report comes out with actual measurements I give it a great deal more weight than mere speculation. In the UK the Muir Trust sponsored a report [backup link] that looked at the UK’s actual wind production numbers and used them to see how the reality stacked up against the hype coming from the wind industry and their government allies. As you can imagine, there wasn’t much of a stack up at all. From the report’s executive summary, here’s the list of industry/government claims they examined.
1. “Wind turbines will generate on average 30% of their rated capacity over a year.”
2. “The wind is always blowing somewhere.”
3. “Periods of widespread low wind are infrequent.”
4. “The probability of very low wind output coinciding with peak electricity demand is slight.”
5. “Pumped storage hydro can fill the generation gap during prolonged low wind periods.”
Here’s the facts, in order.
1. Average output from wind was 27.18% of metered capacity in 2009, 21.14% in 2010, and 24.08% between November 2008 and December 2010 inclusive.
2. There were 124 separate occasions from November 2008 till December 2010 when total generation from the windfarms metered by National Grid was less than 20MW. (Average capacity over the period was in excess of 1600MW).
3. The average frequency and duration of a low wind event of 20MW or less between November 2008 and December 2010 was once every 6.38 days for a period of 4.93 hours.
4. At each of the four highest peak demands of 2010 wind output was low being respectively 4.72%, 5.51%, 2.59% and 2.51% of capacity at peak demand.
5. The entire pumped storage hydro capacity in the UK can provide up to 2788MW for only 5 hours then it drops to 1060MW, and finally runs out of water after 22 hours.
For anyone who’s been paying attention, the disparity between what the industry says and what the actual numbers show should come as no surprise. The report itself is less than 30 pages long and is a fairly easy read.
In addition to the report there were couple of supporting documents, most of which is in the main report also.
The BBC picked up on the story [backup link], which is a little unexpected, as they have been very pro-wind in the past. When a story like this comes out, the wind industry generally responds with ever-increasingly-sincere-sounding assertions. In this case their spokesperson says the industry had “no confidence” in the data. Excuse me? No confidence in data gathered and published by the very-pro-wind government? You may notice they produced no data of their own. They never do. They simply put their fingers in their ears and talk louder. And then have the gall to talk about “scientific”.
And so did the Press and Journal [backup link]. One comment from the government was that renewables generated 27% of Scotland’s electricity. In a discussion about wind turbines, why would anyone quote numbers that included long-standing hydro? Other than to confuse the issue, that is.
Finally, the Scotsman, which didn’t cover the original story, received several letters that are pretty well written. Plus the comments are good also.