The excellent site Picking Losers has this piece on the dys-economics of offshore wind power, which gives us various graphs.

They appear to suggest that the more we invest in them, the less economical they become!

Conclusion:

It all shows that claims that you can calculate what technologies need, rather than simply creating rational incentives and seeing what turns out, is stupid, illusory, and counter-productive. Government never has good-enough information or pure-enough motives for central-planning to be an effective option, whether that planning is implemented by literal command-and-control or through incentives targeted at calculated needs and outcomes.

I could not agree more, as described here.

What makes middle-class people who burble on about the need for a greater role for the state unable to grasp this key problem which necessarily arises from nationalising uncertainty?

Do these people believe in witchcraft?