In the past 10 years.
The supply margin (declared capacity - demand) has reduced by half.
Electricity prices have increased 250%(edit: from 0.11 to 0.25).
And the 9-fold relative increase in imports (1% to 9%) definitely contributes to that increase.
Before you say it's all inflation, I believe inflation is not that high over the same period, and consider the role that electricity price hikes have played on inflation.
Which, in turn, is due to the war.
The main policy failure was the conservative government banning onshore wind for five years. There's less critical issues with pylons and planning that I would actually blame the public for rather than the government.
Other than that, not a lot of other options. People mentioning nuclear will be referred to the build time of Hinkley C.
The transition to decarbonization should have started after 2014. The geopolitical risks were crystal clear back then.
As far as nuclear goes there is a western failure to innovate on design presumably due to ossified regulatory requirements and possible contractor malfeasance. In China new clear plants take 5 to 7 years.
Hmm, I wonder what hugely expensive and distracting project the UK engaged in after that time instead? Ah yes, Brexit, which turns out to have been promoted in part by the Russians (with a lot of help from the UK press and local dodgily-funded actors).
And nuclear had no chance what so ever in the post market liberalization world. Those sudo-market are not design for that kind of thing.
Nuclear made most sense in the area of centralized utilities, but most nations didn't use it well for various reasons.
We don't really need new technology in nuclear, I mean it would be nice but its not really needed.
France has made an absolutely amazing deal by investing in nuclear. If you calculated all the benefits is actually insane how beneficial it was.
This is all true, and yet somehow, at the end of the day, the UK has a higher per capita GDP than France.
That said, its also wrong to measure benefits only by capita GDP.
The conservatives also appear to have intentionally sabotaged one of the auction rounds for offshore wind.