Wind power

Once again you have published comments from members of various wind energy interest and lobby groups heralding another “record” of wind generation (your report, 6 July).

However, the claim that in June Scottish wind generation could have provided electricity for 1.7 million homes is actually unimpressive.

Installed wind capacity in Scotland is about 5.6GW. Were this to operate at its nominal output it could provide electricity for more than 10 million homes. But of course it does not, and this makes these claims both irrelevant and fatuous.

The true measure of the 
usefulness of a generation 
system is not what it produces when, for example, the wind happens to be blowing, but what it can produce when consumers require it.

In June the UK’s 12GW of wind turbines operated at an average output of about 2.5GW.

However, on 6 June they were producing about 7.5GW, more than the National Grid could handle, and so the operators were paid, on that one day, £2 million to turn them off.

On the other hand, on 20 June they were producing only 0.14GW, ie just over 1 one per cent of their notional output and about 0.5 per cent of demand.

It is quite pointless to assert that Scottish wind power could supply all of Scotland’s homes on unspecified and unpredictable six days in one summer month when it could supply essentially none at some other times when there is very little wind, often on the coldest days in winter.

(Prof) Jack Ponton, FREng

Scientific Alliance Scotland

North St David Street

Edinburgh