By Craig Brown, The Scotsman, scotsman.com 30 May 2011
Scotland may have been battered by 100mph gales during the last week but according to latest government statistics, it is facing a 40-year lull that could dent hopes that the country will be able to rely on its wind turbines as a ready source of energy.
Official weather trends have show that 13 out of the past 16 months have been calmer than normal – while 2010 was the century’s “stillest” year.
Experts believe the trend is likely to continue for 40 years – calling into question, among other things, the long-term viability of wind farms.
Scottish ministers were warned that the so-called “breeze freeze” could spell disaster for their plan to power Scotland with ranks of turbines.
Independent energy consultant John Large said yesterday that the Scottish Government had not anticipated such a change in weather conditions. “After the recent storms it may sound odd, but if the politicians and economists have not modelled falling wind speeds into their decisions, then they could find their strategy in trouble very quickly,” he said.
“The SNP’s plans are reliant on private sector investment but if wind speeds drop too far, who is going to put their money into these schemes?”
UK Government figures show wind speeds averaged 7.8 knots (8.9mph) last year, down 20 per cent on 2008, and well below the mean for this century, which stands at 9.1 knots (10.5mph).
Usually Britain has warm, wet and windy winters thanks to Caribbean air carried here by the Atlantic jet stream. But the last two have featured record-breaking low temperatures and were remarkably still when they should have been the most windy seasons of all.
Both extended cold snaps were caused by an enormous patch of high pressure sitting over the UK, diverting the jet stream south.
Meteorologists now believe these becalmed weather systems are linked to levels of solar radiation. A particularly quiet spell between 1645 and 1715 – a period known as the Maunder Minimum – saw Britain suffer a mini ice age, yet also bouts of hot, dry summers.
Professor Michael Lockwood of Reading University said: “We reached a high point of solar activity in 1985. Since then, it has been declining. We are now halfway back to the levels seen during the Maunder Minimum. The probability is that decline will continue for the next 40 years.”
Fellow Reading University academic Dr David Brayshaw warned: “If wind speed lowers, we can expect to generate less electricity from turbines – that’s a no-brainer.”
About 75 per cent of Scotland’s green power comes from turbines.
First Minister Alex Salmond has vowed to create “the green energy powerhouse of the continent”, while the Scottish Government has pledged to aim to secure all of Scotland’s energy needs from renewable sources by 2020, when, it says, it will produce three gigawatts of energy, enough to power three million households.
However, the Scottish Government dismissed the warnings yesterday.
A spokesman said: “The wind will continue to blow, onshore and offshore, allowing Scotland to continue to export ever greater amounts electricity.”
URL to article: https://www.wind-watch.org/news/2011/05/30/blow-to-green-energy-plans-as-wind-speeds-forecast-to-drop-for-40-years/