If intermittent energy would be held to the same standards of sustained energy, you’d see the real price. Right now, the dirty secret is that renewables are integrated into our energy supply by having a crap-tonne of gas capacity (and importing nuclear energy from France) standing ready on poor renewable days.
Go look at any historic data of U.K. power generation. We have multiple periods every year where there’s barely any wind and solar generated for a week. How do you propose to supply exactly every Watt required, at every second of the day, running only on renewables?
If your answer is batteries or pumped storage then please go look at battery storage capacities and what a week of energy needs look like for the U.K.? You’d have to strip mine the entire planet’s worth of supply lithium and other required metals to be able to do it … and if you think nuclear is expensive, have a look at battery storage.
If your answer is “imports” then my retort would be that every country has to solve this problem and we can’t just “turtles all the way down”-solve this problem. On the same days that wind turbines are still in the U.K. they are still in Denmark, Norway, Germany. Where does the energy come from then? Oh, they’ll just import their electricity from Eastern Europe and we can buy their little renewable generation for that week? Ok, but then you’ve just transitioned to coal plants in Poland, by way of a long supply chain. Every country has to solve this problem.
If your answer is “we just need to build such an excess of renewables that we have enough even on still/gray days” then we are back to cost of guaranteed generation, which is how renewable energy providers should be measured anyway. Where does their backup come from? If you held renewable energy supplies liable for guaranteed supply rather than just accept “oh on some days, you can’t generate any power” you’d see a then buy their supply from backup gas. As they currently do, they can just squirm away from the accountability.
Having said that, I’m a HUGE fan of renewable/intermittent energy. We need to build more, fast! Lots and lots more.
But we do have to answer the uncomfortable question of how we back it up too. That’s included in the price of nuclear.
So what do we do? Import our way out of it, moving the generation to remote, cheap, foreign coal? Over, and over-build renewables, thereby making it extremely costly. Accept gas peak generation, thereby keeping carbon in the mix? Or nuclear?