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Comment by cyberax | Hacker News Reader

> Some European countries have already stopped using fossil fuels

Yes, the ones that have classic hydro.

> Cheap electricity is going to be important for national economies and there are no countries that couldn't build cheap wind and solar (and/or cables to import neighbours' excess renewables production).

Solar and wind ARE NOT cheap if you actually want them to be reliable. They are about 5x-10x more expensive than nuclear power in this case.

The problem is called Dunkelflaute. Here's an actual example: https://energy-charts.info/charts/power/chart.htm?l=de&c=DE&... - renewable generation mostly disappeared for a week from 18-th to 25-th. These kinds of events happen almost every year, and often more than once.

Worst-case modelling shows that Germany can get about a _month_ of sustained Dunkelflaute about once in a century.

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We are not stuck and these issues are solvable (as much as they exist): trade of electricity with neighbouring countries, storage etc. For example, a simple thing where Germany could try to follow the Nordic countries is heat pump installations to keep houses warm without fossil fuels.

It is true that heating should be electrified … but it’s important to note that this makes the Dunkelflaute problem more serious, not less.

Because now your inflexible base-load has increased. And while spreading generation over a wider area helps, it rapidly reaches limits (unless your power grid extends close to the equator).

It makes it less serious in the north where shortage of electricity would mean freezing indoor temperatures. Heat pumps have reduced the amount of electricity needed (compared to direct electric heating) for heating a house and thus the amount of imports/storage needed. Also, if the heat pumps are a part of a district heating system, a heat storage solution can be included in the system.

In a country where heating isn't yet electrified, it's a way to reduce fossil fuel use and carbon emissions (the ultimate goal) without necessarily reducing the fossil electricity production. So even if it doesn't solve Dunkelflaute alone, it's a part of solving the climate and energy crises.

Germany is complicated, because they mostly use gas for heating, not electricity. So switching to heatpumps will require more generation. And for now this means new natural gas plants.

This is not _too_ bad in itself, using gas for generation and then powering heat pumps is more efficient than burning gas for heating. But the capital requirements for new power plants will cement Germany's dependence on fossil fuels for at least another 2 decades.

It's a mess.

> We are not stuck and these issues are solvable

I don't believe they are solvable with the existing approaches. Transition to natural gas from coal is possible, but there's nothing on the horizon after that.

The existing plans (if you can call them that) mostly depend on asterisks pointing to a footnote saying "magic happens here": cheap hydrogen, power-to-gas, radically cheaper batteries, etc.

> For example, a simple thing where Germany could try to follow the Nordic countries is heat pump installations to keep houses warm without fossil fuels.

They are trying. But they are already having problems with very expensive electricity. Which will only get worse, as demand climbs with more heat pumps.

> there's nothing on the horizon

We can build more of what we have, such as pumped hydro and EU-wide interconnections.

You mentioned the fear that the solutions will cost 5 times more than nuclear. That's not a horrible worst case scenario (as nuclear is so cheap ;-) and we can be sure that costs go down as the markets scale and technologies mature.

It may look bleak in Germany at the moment, but it certainly doesn't look bleak everywhere or for long.

a lot of the answer here is hydro. currently, hydro is seen primarily as a generation method, but as the amount of solar and wind increase, hydro increasingly becomes an easy way to fill the gap from dips in production. another short term answer is natural gas. if you run a natural gas plant 1 week a year, it's not ideal, but it's still 50x better than running it all the time.

I've read several studies that say that you're wrong. You need to get your information from other places than nuclear trade organizations.

The reason storage hasn't been yet been addressed much is simply that the demand is not there yet. But as one example, you can produce biogas and use the existing gas infrastructure.

> I've read several studies that say that you're wrong.

Well? Where's the plan then? The ones I've seen require taking a very stiff dose of crack and meth to make them believable.

> The reason storage hasn't been yet been addressed much is simply that the demand is not there yet.

Well, yeah. Europe has no capacity market, so cheap low-quality solar/wind is a good way to get return on investments. And wintertime generation is supported by fossil fuels that are still too cheap.

> But as one example, you can produce biogas and use the existing gas infrastructure.

"Biogas" can support only a tiny amount of consumption. Power-to-gas (methane produced from water and captured CO2) is an option, but the round-trip efficiency is poor and costs are too high.

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