From NOT A LOT OF PEOPLE KNOW THAT
By Paul Homewood
NESO have published their Winter Outlook, assuring us that we won’t run out of electricity this winter:
Britain’s electricity supplies expected to remain secure this winter
Building on our Early View of Winter Outlook published in June 2026, our outlook remains largely unchanged, with enough electricity supplies to meet demand throughout the winter.
This report provides a more detailed assessment of the winter ahead. The reported margin is higher than in our June outlook but this is due to improvements in the assessment methodology, not a change in the overall outlook. For a complete picture, this report should be read alongside National Gas’s Winter Outlook 2026/27.
https://www.neso.energy/publications/winter-watch
That’s all very reassuring.
But just one minor problem – their outlook assumes the wind does not stop blowing!
As their report describes, they take into account “de-rated” margins. This is designed to allow for the fact that generators will never work 24/7. A CCGT plant, for instance, is assumed to be available for 90.5% of the time, as there are always breakdowns and planned maintenance.
Individual plants might be unavailable for days at a time, but across the whole CCGT fleet, we should be able to rely on at least 90.5% being available at any one time.
But, as the last box notes, NESO are assuming a de-rated factor of 16.5% for wind power, which works out at 5.4 GW.
We know that wind power across Britain sometimes drops well below 5.4 GW. Indeed only yesterday it ran at less than 3 GW for several hours:
In extremity, there have been some winters when wind power has dropped below 1 GW. Wind is so unreliable that it should not really even be factored into NESO’s contingency planning.
Below is the relevant section in NESO’s Workbook:
They claim they have a safety margin of 5.9 GW, but this all but disappears when wind power is taken out.
They are already relying on 6.6 GW of interconnector imports, not to mention 6.4 GW of storage, which will only be available for an hour or so at peak times:
If we don’t get a dunkelflaute, we will probably just about muddle through, but only by maximising gas power and imports.
In the meantime, keep your fingers crossed.
NESO are trying to pull the wool over our eyes and it shows just why they should never have been set up as a Government owned body.
They clearly are not independent and from the start have had imposed on them the twin conflicting of objectives of pursuing clean and reliable energy. The two are totally incompatible.
Their first priority should always have been reliable energy.
