PowerSwitch

https://www.bbc.co.uk/news/live/cq5n92qpdxzt Previously announced targets now said to unachievable.

I suspect that politicians fell into a common trap of assuming that if carbon emissions can be reduced by say 50%, Then another 50%, down to zero must be similarly achievable. In fact the second 50% is much harder to achieve than the first.

Having a very attractive Energy (called net zero these days) Minister doesn't escape the reality you mentioned.

The problem is that the first 50% is the amount supplied by the naturally variable nature of renewables, both on a daily and yearly basis, and the rest is supplied by existing fossil fuels and nuclear (or is this net zero?) stations covering the times when renewables are not available or have not been stored for such an eventuality as there is not enough new storage and/or not enough an excess of renewables built yet.

You will probably find that the first 50% of renewables generation is getting used to supply power 'most' of the time that they can. If you build more renewables, enough to get to say, 75% renewables, you will find that there are a lot of times the power from these is not needed, i.e. you are generating too much and excess generation will be spilled, in industry parlance. This probably why all these undersea cables are getting built to supply neighbouring countries that probably don't need the power at this time either.

I would propose that it needs about the same expenditure again to get from 50% renewables to 75% as it did from 0% renewables to 50%. Then probably the same from 75% to 87.5% etc etc. A kind of inverse Moore's Law for energy.

Probably the only thing that will stop this happening is cheap storage, and maybe there are a lot of possibilities for variable large loads such as long term heating or industrial processes and municipal uses such as water treatment and pumping. Perhaps the industrial workers of the future, assuming there are any left in Western societies will get the day off when it is not windy or sunny enough.

In the days of wind mills for grinding flower, you worked when the wind blew. Water mills were more expensive to build, but would work more days of the year, less frequently in summer. The miller was not a popular profession in medieval times, they effectively had a monopoly on flour. The decided which of their customers got to eat, and which had to trade wheat for flour from their neiighbours. The miller always lived well, and got a lot of time off.