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"overbuild" - by what factor? For example, Europe is quite far to the north and that means very cloudy winters over most of the continent. If the wind blows, f
by inglor_cz 2y ago
"overbuild" - by what factor?
For example, Europe is quite far to the north and that means very cloudy winters over most of the continent. If the wind blows, fine, but you can also have several days without wind, when both wind and solar north of the Alps generates basically nothing.
Oh yes, the Spanish meseta will probably still be sunny, but the amount of solar that would be needed to power the rest of Europe for several days probably won't even fit there (not to mention how robust would the pan-European grid have to be to tolerate such flux of energy over thousands of kilometers and ten country borders); and if it does, what will you do with all that extra power in summer?
The fact that real (as opposed to nominal max) output of wind and solar fluctuates in a 1:100 range based on factors that are hard to predict more than a few days in advance is really hard to square with the demand for stable grid. It is a big, fundamental problem.
- pfdietz 2y agoIn Northern Europe, rare occasional Dunkelflauten are best dealt with by an e-fuel backup. The RTE of e-fuels is lousy, but because these events are uncommon that doesn't matter much. Europe has ample geology for storing hydrogen, so it would likely be the e-fuel used. A simple cycle combustion turbine power plant has a capital cost of maybe 5% of a nuclear power plant; combined cycle, about 10%. So one can substantially back up the entire grid with these at a capital cost low compared to that of powering the grid by nuclear.
- inglor_cz 2y agoMethanol might be more practical. Theoretically, you could put floating wind turbines onto the sea in places that have almost uninterrupted wind (they are mostly far from land, though), let them produce methanol and use it as a e-fuel. It is much easier to transport and store.
- pfdietz 2y agoFrom what I've been told, if you have salt formations for hydrogen storage (and Europe does) then hydrogen is better than trying to use methanol. The latter is much more complicated and has lower round trip efficiency, involving storing not just methanol, but also CO2 and oxygen (from electrolysis, to use in oxyfuel combustion to help recycle the CO2).
- mpweiher 2y agoThe problem is that you need the infrastructure to create the e-fuel or H2 gas. That infrastructure is expensive. And will be sitting idle most of the time.
- pfdietz 2y agoYes, the electrolysers have to be sufficiently cheap. But this is happening; I understand China now gets 4% of their hydrogen from electrolysis.