[Taig]

> It's hard for renewables to replace coal or nuclear though, because coal and nuclear provide baseload power, whereas wind and solar are very intermittent and require basically 100% gas backup (as there will be circumstances with very low wind and solar, which tends to happen in europe on very cold, still, winter nights when demand is the highest).

I absolutely agree with you that we need the coal plants and imports for base load. For a fully renewable grid, we need massive storage capacity. This, however, is far from an unsolved problem. The problem is that the economic incentives aren't aligned with that goal yet. There is reason to be optimistic though, and that the money Germany is saving on nuclear, is more sustainably and effectively spent on renewables and storage.

[eldaisfish]

How is energy storage a solved problem? All the battery storage in the world today would power half of Germany's minimum electrical load for minutes.

[adrianN]

Germany has enough storage capacity for natural gas to last a couple of months. The same can be build for Hydrogen. Some of the existing infrastructure can even be reused.

[martinald]

Yes but you need 10s or 100s of GW of hydrogen electrolyzers, which are expensive, and they will only be running a small % of the the time (when there is excess renewables).

I'm not sure how much existing natural gas infrastructure can be reused given how much lighter hydrogen is and I assume it needs much tighter tolerances on all the equipment compared to natgas.

[adrianN]

Yeah, true. But it turned from a "we don't have enough of element XY on Earth to build that" to a "it sounds kind of expensive" problem. As it turns out people did the math already and building the hydrogen infrastructure is probably not prohibitively expensive, in fact it might turn out to be reasonably cheap. There is a tradeoff between overbuilding renewables, improving the grid, making the demand side more dynamic, and storage.

[martinald]

Yes, but my point isn't so much it couldn't ever be done, it's that by the time you upgrade the grid massively, build the renewables, build the electrolyzers, build the hydrogen infrastructure and the infrastructure to convert it back to electricity, it's almost certainly way more expensive than already expensive nuclear to build.

[adrianN]

The experts tend to disagree.