New figures compiled by Imperial College London's Rod Gross revealed July's wind output was down by 40 percent so far compared with the same period last year.
He said: "We've been typically doing between two to three gigawatts of wind [generation].
"At a windier time of the year we might be doing nine or 10."
The unusual stillness in the air is the result of a sustained period of high, dense pressure over the UK, according to the Met Office.
A Met Office spokesman said: "It's like a lid, it keeps everything still.
"From the forecast looking out
over the next couple of weeks, there doesn't seem to be any significant change on the way."
A National Grid spokesman said: "Between June 4 and July 15 wind generation was around 30 per cent lower compared to the same period last year.
"Electricity demand is low and we're comfortable with the level of spare generation we have available.
Comment: In light of a recent study showing global wind speeds have been
decreasing since 1960, meanwhile extreme winter storms and wave heights have been increasing over the last
70 years, one wonders whether this will become a repeating pattern and what
other changes may accompany it. And if it does become a repeating pattern those
supporting unreliable renewables, as evidenced
elsewhere, will sorely regret their ignorance.
Comment: Global cooling: Excessive spring snowfall results in non-breeding year for shorebirds in north-east Greenland - 1 meter deep snow