Doesn the dirty back-up power required when the wind stops blowing mean that the CO2 saving is wiped out?
This rather bizarre claim is increasingly commonly made by anti-wind campaigners. Their argument is quite simply wrong. The national grid needs back-up regardless of wind power because it is needed for all forms of energy generation to cover unexpected increases in demand (a cold snap in winter, England playing football on television, etc). In fact, one of the biggest back-up requirements on the system these days is because of Sizewell B nuclear power station. When it fails (as it has done recently due to safety concerns) it knocks out a huge amount of capacity in an instant – unlike wind, where any variation is both gentle and predictable. Only when there is a very large capacity of wind on the system (above 10%) will the variability of the wind become noticeable over the normal variation on the system. Only then will any of the required back-up be specifically due to wind power, and only at this point could any carbon emissions from back-up plant be counted against wind power. In fac
