By Paul Homewood
One of my regular contacts has analysed wind power data over the last five years, using the official half-hourly National Grid data.
The analysis highlights just how intermittent wind power can be:
https://www.nationalgrideso.com/data-portal/historic-generation-mix/historic_gb_generation_mix
Periods when wind meets less than 20% of demand are labelled as Wind Scarcity, and would roughly equate to wind power running at about 25% of capacity. This is not low by any means – as we have seen before, wind power often drops to less than 5%. The calculation for 2023 of 3219 hours represents 36% of the year, so these periods can be regarded as perfectly normal weather.
If we fast forward to the 2030s, we might expect wind capacity to double, but equally demand is likely to be 50% greater too.
In broad brush terms then, the above calculations for 20% of demand, will apply to something like 28% of demand in the 2030s, when average annual demand is projected at around 50 GW. In other words wind might only supply 14 GW at most for 3219 hours a year, based on 2023 outputs. Remember that 14 GW is the maximum – for most of that time, wind output will be much less still.
When gas power stations are shut down, we may only have about 10 GW of dispatchable capacity, from biomass, nuclear and hydro, plus possibly 20 GW from interconnectors. On these figures, we will be short of power for more than a third of the year.
Some of this time may only last for an hour or two at periods of peak demand, but that begs the question of whether we will have enough surplus power at other times of the day to either store electricity or shift demand.
Other exercises have looked at wind droughts that last days on end. This new analysis suggests even in periods of normal weather, we still won’t have enough wind power to run the grid.
NOTES
I can pass on the spreadsheet to anybody interested.