Pity National Grid managers the other week when the country was blanketed by thick cloud and the wind was barely above a breath. At 0830 coal was already being burnt in power stations to keep the lights on and trains running, and it was burnt throughout the day. Nuclear also ran all day as it always does.
The Grid keeps quiet about these sort of days – the days when some of the greener electricity retailers have to phone customers asking them to turn off appliances. In days to come, of course, they'll be able to do that remotely via your smart meters. And eventually they won't have to ask because you'll have agreed to let them do this in exchange for keeping price rises "modest".
We should note that no matter how much installed wind generation there had been on that day there would not have been enough generation to meet demand. So the understandable urge to build more and more turbines has its limits.
Then there's the future when we all have electric cars charging at home (7kw for hours on end), heat pumps (another 2 kw maybe also for hours) and electric cooking. Given that the average house uses 7kw in winter, this could mean more than a doubling of demand, mostly from low level and intermittent sources. Where is this electricity going to come from? And how will an ageing Grid, designed for a different age, cope?
Answers to questions such as these never seem to feature in green announcements from the prime minister.
I read that we now have more than 10,000 turbines in and around the UK. These have a theoretical maximum output of 24 gigawatts [GW] if all are turning optimally. Typically, they average about 8 GW with lows of around 3 GW. I also read [in The Times] that when the Grid calculated how much power Britain needed this winter, it assumed that wind would only deliver 16% of its maximum (and half the average). This is also partly due to difficiulties in getting the power from where it is generated to where it's needed. This is a North – South issue. Think bottlenecks and electricity jams, and eye-waveringly expensive inter-connector cables that don't actually work.
So, thank goodness for nuclear and gas because we shall be needing them a lot for a long time. Someone has to think these heretical thoughts.