Utilisation and costs key for wind power

THE electricity grid always copes with huge variations in demand, depending on time of day, weather and other factors, by keeping a proportion of generation as spinning reserve which can accept load in seconds and starting up additional plant as required.

Variations in load and in wind power are both predictable by forecasting the weather, so nothing has changed. Ray Dunne is wrong; it takes hours, not weeks to bring additional plants online, and the spinning reserve generates about 5%-10% of rated power, which is used and not wasted.

It is meaningless to talk about the efficiency of wind power because the fuel is free; it is the utilisation factor (25%-40%) and the installation cost that matters.