> Now if only the UK didn't have an insane system where all electricity is purchased at the highest cost in the mix.

That isn’t a “system”. It’s just what happens. Why would the 99% RE be forced to sell at a lower price? They will sell at whatever the market value is. Which is determined by supply and demand. And the gas turbines will only turn on if it becomes profitable for them to turn on at that price. So the causality actually is the other way around. Lots of demand increases electricity prices, higher electricity prices make it profitable for more expensive means of production to be powered up.