From NOT A LOT OF PEOPLE KNOW THAT

By Paul Homewood

When it’s a windy day, guess what? We get a lot of wind power!

Yesterday we got 60% of our power from wind:

It does not take a genius to work out that when Ed Miliband succeeds in tripling wind power capacity, there will be far too much wind power for the grid to handle.

I have analysed the half hourly generation data for the full winter just gone. It’s a fairly basic summary, but my model assumes a tripling of wind output, 4400 MW of fixed nuclear generation and existing demand profile.

It calculates that there will be 19 TWh of surplus wind power during those periods when wind and nuclear exceed demand. Obviously there will be other periods when wind and nuclear cannot supply all demand.

Whatever battery storage we have by 2030 will be far too tiny to make any difference, so most of that 19 TWh will have to be constrained. At a going rate of £100/MWh, that could cost £1.9 billion. And this is just for winter.

With much lower demand in summer and plenty of solar power as well, plenty more surplus electricity will have to be chucked away.

The problem is probably much worse still. Although I have not factored in higher demand, the increased proportion of offshore wind in the mix will increase wind generation above my projections.

There is also the issue of grid stability. I cannot see how the grid can operate stably with above 90% of generation coming from wind at times. Including some dispatchable power to stabilise the grid will automatically increase the projected surpluses.

Thirdly is the question of regional imbalances. Will the grid be able to cope with large amounts of wind power coming from Scotland and the North Sea? It is, of course, lack of transmission capacity which results in constraint payments to Scottish wind farms. OFGEM is busy spending tens of billions upgrading the grid, but whether even that will cope in future must be debatable.

Some of the surpluses are massive, as much as 32 MW on one occasion. Surpluses were above 20 MW on 16% of the three month period. The model also predicts that more than half of wind generation will have to be constrained for 10% of the time.

The practical difficulties faced by NESO in having to implement all of this, every half hour are mid boggling.

Just a glance at yesterday’s generation shows how huge the problem is. Demand was 35.9 GW. Of that, 21.5 GW came from wind and 3.4 GW from nuclear. Triple that wind capacity and you are looking at about 68 GW from wind and nuclear.

Half of that will have to be switched off on average, and more at times of low demand.