Windfarms only giving half power

Scotland's wind farms have produced only around half the amount of power they were expected to this year. The government blamed the low generation levels on unusually calm weather, but critics said the figures showed the danger of becoming too dependent on renewable energy.

For example:

  • Turbines are expected to operate at an average output of about 30 per cent of their maximum installed capacity.

  • But the average output over five months this year was 17 per cent – just over half the expected average.

  • There have been long spells when virtually no electricity has been produced by any of the country's wind farms.

    "This raises serious concerns about security of supply. We have always been told that even if it isn't windy in one part of the country, it will be elsewhere. However, this suggests that is not the case," says Helen McDade, head of policy at the John Muir Trust, which campaigns to protect wild lands in Scotland.

    Stuart Young carried out the research by analysing data from the Balancing Mechanism Reporting System Website, which the National Grid uses to monitor generation. The site provides a constant flow of information on output from 1,588 megawatts wind farms in Scotland:

  • His research showed that for 80 per cent of the time between February and June, Scotland's turbines were operating at less than 30 per cent.

  • And for almost a third of the time they were operating at less than 5 per cent of their maximum output, meaning they were virtually becalmed.

  • Only nine times between February and June had the wind farms achieved 30 per cent efficiency for a full day at a time.

  • There were long stretches, such as from May 16 to 29, April 9 to 15 and February 6 to 23 when they failed to reach 30 per cent output.

    "At the moment there's not a big enough penetration of wind to cause National Grid a problem, but the more we rely on it and the less we use fossil fuels the more likely there is to be a set of circumstances when – with very high demand and very low output – the only thing is to turn customers off," says Young.

    Source: Jenny Fyall, Windfarms only giving half power, The Scotsman (UK), July 18, 2010.

    For text:

    For more on Energy Issues:

    First published by the National Center for Policy Analysis, United States

    FMF Policy Bulletin/ 27 July 2010
  • Help FMF promote the rule of law, personal liberty, and economic freedom become an individual member / donor HERE ... become a corporate member / donor HERE