I believe you’re a little confused.
> But [nuclear] takes the most time, cost hilarious amounts of money
Depending exactly what you mean, this is either very true, or dead wrong. It is true that a single nuke plant costs gigantic amounts of time, money, and resources. But it also deliver significant power, typically 1GW (sometimes a bit less, generally more). Windmills are vastly cheaper, but typical ratings are around 1MW, and that’s a maximum, not an average, and if you need to control energy output you’ll need a buffer (batteries, flywheels, dams…).
To replace a single nuke plant, you’ll probably need something like 2000 windmills, and energy storage to match. Or less if you’re okay with temporary power shortages (a harsh but valid political choice).
Now which is cheaper? One nuke plant? Or 1-2K windmills? All those windmills will need a lot of concrete, for which we’re destroying quite a few beaches (desert sand does not work unfortunately). You’ll also need quite a bit more rare earth materials to get that thousand dynamos to work. And eventually you’ll need to transport all that in a world without oil (one reason renewable energy is cheap is because transport is still cheap, thanks to oil).
> We need technology which is cheap, deployable before it is too late to reduce our emissions and accessible for every country on this planet.
Agreed.
> if you really care about the environment and are not merely one of those people who blindly recite Michael Shellenbergers
Here’s my main source: https://jancovici.com/
One thing to note: the guy doesn’t even pretend nuclear power will replace what we have now. He’s just saying that no matter what we do, our energy consumption will inexorably go down, and that will start soon, if it hasn’t already. Since energy is a physical measure of how much we can transform our world, that means we’ll be able to transform it less and less, a.k.a. the economy will shrink, a.k.a. big ass long term recession. And that’s before we make it even worse in the name of staving off global warming.
His thesis is that nuclear power will not be enough to stop the fall. But it might significantly soften it, and we can only hope that it will be enough.