Professional Engineering

Dr John Jones, School of Engineering, University of Aberdeen, implies criticism of the British Wind Energy Association, Letters, 24 August 2012. 

They are indeed quite wrong to say, “even at low wind speeds turbines are producing electricity”. In fact, the Nordex sales brochure tells us their 2.5MW machines produce zero below 4m/sec, 9mph.

On 2nd February 2012 our Grid-metered wind turbine fleet, with a capacity of 4,219MW, was actually generating 32MW at 1630 hours, the maximum power demand time on that day. It was within one of the many anticyclonic spells that we experience each year. They last for some days, often a week, maybe 2-3. Those light winds cripple wave machines too.

In the late May one, on the 24th, our then 4,686MW wind fleet was actually delivering just 8MW – one sixth of one hundredth, 0.17%.

Within those anticyclonic spells we still have solar output declining from mid-day to zero at dusk, rising slowly from dawn. The Moon continues in its orbit, giving zero output from tidal flow machines at slack water, four times every day.

Meanwhile about 25 million UK dwellings each burn an average 15,000kWh of gas every year for space and water heating. A figure of one kg CO₂ for 3kWh has been used – a lot of pollution, anyway.

And all that energy could be supplied carbon free by a combination of nukes, storage heaters and 200ltr hot water storage tanks. Better still, if we have the nukes, the other part would all happen naturally, with ordinary market forces, no subsidies, no taxes, no despoiled rural scenery. And in daytime, more fossil generation could be displaced.

Bill Hyde, Offham, Kent

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