Wind Speed in Decline: A Blip or a Trend?

It has been knuckle chewing time for the last couple of years for those wind farms that have been stupidly built in the less windy parts of the country. Even those built where the wind actually blows have seen their profitability massively cut. But those who had been planning to cash in on sub 20% capacity factor outputs are now beginning to feel the heat.

Of course we all know that none of them were, are, or ever will be, viable without a massive ROC subsidy. But even with this subsidy some must now be trading on the margins of viability.

Last year for example the output of all UK wind farms fell by 7%. Yet in that same year many more turbines were built. The theoretical (some say imaginary) total wind-farm capacity increased by 13 %.

To me, that looks like over a 21% drop in total.


An unpredictable long term reduction, getting worse year on year. Just what the bankers want to hear (not).

2009 wind speed was low, last year it was lower still.

So, is this a blip? Or is it a long term trend?

Oh, such a quandary and who has the answer?

Actually it is our friendly BWEA to the rescue. Or rather a paper presented by the doyens of the Wind Turbine fraternity: Garrad Hassan and Partners Ltd

I hasten to add this paper was presented first in 2006 and is now dated 2009, both dates are before the current downturn.

You can find the PDF of their paper Here  (if it disappears, Billothewisp has a copy)

It is titled:


The running 15 year trend with wind speed, according to Garrad-Hassan is as follows

It is going down. Now remember this was up to 2005.

Garrad-Hassan then tried valiantly to use some weather indices as proxies to go back further. Back to the 1960's in fact. The most important of these is the North Atlantic Oscillation (NAO) then there are two other indices used. One is Katalog Der Grosswetterlagen Europas. This is a subjective catalogue of large scale weather patterns over Europe dating back 100 years. Then finally they also used the UK Jenkinson Lamb weather classification (which is similar to the Grosswetterlagen catalogue but for the UK)

Here is what they found for the NAO

here is the Jenkinson Lamb result

Finally here is the Grosswetterlagen graph

Notice how they all roughly correlate.

Also notice the "blip" around 1995.

In their conclusions, Garrad-Hassan try and sweeten the pill of the 15 year decline by suggesting that all that was happening was that wind was returning to stability after a upward blip in the mid 1990's.

However we should remember that this is then essentially returning to a stable "low" wind-speed. Garrad-Hassen re-assuringly write that a further fall in average wind speed should not be assumed. Though, they could not rule it out.

But of course, this Garrad-Hassan data only goes up to 2005. Since then we know that things have actually got worse (significantly so in the last year)

So, are we just bottoming out? Or are we still going down?

Perhaps our previously loan happy banking fraternity should look a little more closely at what they might be letting themselves in for.

Maybe the wind turbine carpet-bagging fraternity will be seeing that big red stamp that spells out "DECLINED" being used a little more on their loan applications from now on.

Maybe a few of their pals who have built these things in totally inappropriate areas will soon be queuing up at the local Licensed Insolvency Practitioners office.

Then I expect the poor bloody rate-payer will have to fork out to pull the things down.

What a waste.

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