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by benj111 2556 days ago
Good point, it's relatively easy to get to 70/80/90% renewables. Its that one week in January, where its cold, the wind isnt blowing, it's cloudy and your nuclear reactor is down for whatever reason.

But most countries seem to be shifting to gas away from coal in the short term, wouldn't gas generation be better for that kind of situation, ie if you have mothballed gas and coal generation, why keep the coal around?
2 comments
adrianN 2556 days ago
Gas is better in the situation where you have overbuild renewables enough to afford power-to-gas systems as energy storage.
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AstralStorm 2556 days ago
Gas is no better than coal from climate PoV, and it is much harder to source locally in many countries.
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tialaramex 2556 days ago
Nope. Gas is _much_ better than coal from a climate POV.

Natural gas is basically methane, CH4, when you burn it you're making CO2 and H2O (water) and you get energy out from both these changes.

But coal is much nastier, not only is there nitrogen and sulfur in there (which are both going to produce poisonous gases you'll need to do something about) but the ratio of carbon to hydrogen is much worse so we produce far more CO2 for the same amount of energy production.

Shutting coal plants and building gas plants instead makes a big difference. Not enough of a difference to prevent catastrophic climate change, but a big step in the right direction compared to subsidising coal.

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andrekandre 2556 days ago
yep, and not only sulfur and nitrogen but also radioactive!

https://pubs.usgs.gov/fs/1997/fs163-97/FS-163-97.html

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benj111 2556 days ago
No but its better from a start up quickly point of view? I don't really know anything about the startup procedure for a power station that's been off for 6 months, I would guess gas is easier?/quicker?

I'm unsure if its better from a storage point of view. Yes you can pile up coal in a field, but I'd prefer a tank of gas. And there should be infrastructure for storage left after households move away from gas heating.

I'm speaking from a UK POV, the model would seem to hold for Europe and North America at least.

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cygx 2556 days ago
Naively, replacing coal with gas will decrease CO2 emissions by 40%. Not sure how this changes once you factor in supply chains, etc.
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