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Comment by _ph_ | Hacker News Reader

Nuclear plants are not a real replacement to gas. First of all, a lot of gas gets used for heating - nuclear isn't useful there. Then it is used for providing flexible power, to ramp up and down as quickly as possible to follow the production of renewables. Only a small fraction of the gas goes into "base load" usage. So the government might look into the nuclear power plants to dampen the price level for electricity a bit, but that is about it.

For the last days, there was a lot of wind in Germany, causing the German wind energy production to sometimes even exceed French nuclear (up to 48GW of wind power). Germany most of all now has to correct the mistakes by the previous government and very quickly has to push for building up more wind and solar capacity.

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The only reason gas is used for heating is the historical cheap price for gas. Gas line and gas infrastructure is actually a bit expensive and require additional maintenance compared to just running electrical lines between homes, and gas heaters are generally a bit more complex to install than electric heaters. The incentives to continue with gas heaters goes down when gas prices goes up, in similar way that the incentives for electric heaters will go down when the electricity prices goes up.

If we compare Sweden to Germany, almost no homes in Sweden has gas lines connected to them. Swedish homes use heated up water (central or communal heating), or just heat up the air. Sweden has a lot of nuclear and hydro so the electricity prices has historically been low, and importing gas would be expensive. There have been few incentives to spend money and government resources into the infrastructure needed for gas. Germany in contrast seems to have done the opposite, with historical low prices for gas (didn't the coal industry produce also produce gas in the past?), and fairly high prices for electricity. By now there is a pretty large sunk costs into gas infrastructures, and a switch to electric heating would be both expensive for the government and for individual home owners.

On the positive side, a massive investment towards electric heating would be a major boon for the environment. Leaks from natural gas is considered a major contributor for green house gases, and burning it also not very good.

Sweden has 8x less residents then Germany tho

People always come up with this population-size argument in contexts where it's totally irrelevant[1]. So what if Germany has eight times more residents than Sweden, or Sweden eight times fewer than Germany?!? Everything still works the same, only scaled up or down by a factor of eight: You have eight times more/fewer consumers to supply (with energy, staplers, food, whatever), but you also have eight times more/fewer entrepreneurs and workers to supply it.

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[1]: This moronic argument is most frequently brought up as "Single-payer health care can't work in the US as it does in [insert any country with single-payer health care], because the US population is [X] times bigger!" Yeah, but so fucking WHAT? That just means the US has X times more health care recipients, and an X times larger economy to supply health care! It's just the same thing, scaled up by a factor of X. Sheesh...

It's relevant, but I'm no expert by how much. Sweden has tons of hydro, Germany has none. Scaling infrastructure is hard af.

How is population size relevant to the occurrence or lack of geographic / geological features?

> First of all, a lot of gas gets used for heating - nuclear isn't useful there

All electricity basically turns to heat at some point. So why not?

Yes, of course you can heat with electricity - and using heat pumps this is definitely the future. However, the amount of nuclear available would make only a small difference here. It should be much easier to just buy gas internationally and push forward with renewables.

You can also use the heat directly (district heating) without having to go to electricity and back. This limits the electricity output efficiency but increases the overall efficiency of the plant. It requires changes to the turbines and the buildout of a district heating system though.

Sure you could heat with nuclear directly. Actually that sounds like something that should have been done when nuclear was in fashion. But you would have to produce a lot of new infrastructure and most of all, new nuclear plants. None of the existing nuclear plants is suitable for that.

And that is sure, while keeping the remaining nuclear power plants in service a little bit longer might be a consideration (though unlikely), investing in new nuclear infrastructure for sure isn't. There, renewables are the way to go.

Germans can barely get their heads around nuclear energy. Pumping fluids that have been anywhere near a reactor into homes will be untenable.

I don't think this is the core problem, that would have been to build a nuclear reactor so close to a major city, that you could run a pipe to it.

As you can tell from the map that's not really an issue. Nuclear power plants aren't in the middle of nowhere, they need access to an educated workforce.

https://www.researchgate.net/figure/The-map-of-Nuclear-Power...

They aren't in the middle of nowhere, but usually quite a bit away from city centers, for safety reasons. Too far for a hot water line to be practical.

Up to 30km is no problem for water between 90-175 degrees celcius, so you reach plenty of cities.

https://doi.org/10.1016/j.apenergy.2018.02.080

SMRs operating at atmospheric pressure, or otherwise more managable due to smaller scales may alleviate that.

https://waerme.hamburg/presse-media/pressemitteilungen/erneu... <- This is one such plant at the western edge of Hamburg, being remodeled for that use-case. Having recently seen workers from Statnett climbing the masts in the rain to put pilot wires to pull new wires(80MW upgrade) on one half of the masts, while hearing the 50hz-buzz about 25 to 30 meters below. Crazy Vikings! :-)

You lose something like 70% of the thermal output of the reactor in the conversion to electricity. Also the capacities a nowhere near large enough. Nord Stream 2 alone can transport something like 63 GW worth of gas. This is more than the total electricity consumption of Germany.

And for a home heater, 80% of the heat from the gas you burn goes up the chimney.

Larger energy capture devices can be more efficient. One highly-efficient fuel burning plant providing power to a hundred thousand electric resistive heaters can produce more useful heat per unit fuel than a hundred thousand small-scale self-maintained home furnaces.

I think you got your numbers wrong. Even in the US, you are not allowed to sell gas furnaces with less than 80% efficiency. High-end ones reach over 99% efficiency.

Your numbers are totally off. When did you bought and installed the last heater?

Modern condensing heaters have an efficiency of 90%.

You're both wrong.

Combined cycle power plants can be 64% efficient [1] at turning heat into electricity. And if that power goes on to run a heat pump, 1 watt of electric power can deliver 3-4 watts of heating.

And modern gas combi boilers can be 92-98% efficient [2].

The days of people throwing away 80% of the energy they pay for are long gone.

[1] https://en.wikipedia.org/wiki/Combined_cycle_power_plant [2] https://www.which.co.uk/reviews/boilers/article/boiler-energ...

Could you give some examples for nuclear power plants that are using a combined cycle turbine? I was under the impression that the operating temperatures of BWRs or PWRs are nowhere near high enough for that.

You can't use electricity to run your gas furnace.

Green hydrogen derivatives would make that theoretically possible. This is receiving quite a lot of attention in the EU at the moment. In practice, the stress is more on industrial processes and other primary energy use scenarios.

https://waerme.hamburg/presse-media/pressemitteilungen/wasse...

But if you use that gas furnace to heat radiators in a fluid-born (usually water) heating system, you only need to install an electric heater next to your furnace and re-route the pipes to/from the furnace to use that heater in stead. Not all that humongous an operation.

Maybe because 90%* of all houses need to be refitted.

(*estimated number out of thin air, but yes majority is gas or oil)

In the UK, air source heat pumps are pushed as a 1:1 replacement, with running costs basically the same as gas, in GBP.

I can’t verify that easily, but this doesn’t seem disputed, so the retrofitting is maybe not so much of an issue. There is of course the initial installation cost, but also presumably lower maintenance costs.

Nobody here uses electrical heating. It's all done with radiators and the like, pretty much exclusively.

https://news.ycombinator.com/item?id=30439403

And heat pumps work much better than induction generally.

It also isn't politically feasible. Nuclear power needs subsidies and I doubt a green government will restart those. Government can be impulsive, but I don't see that happening again.

In Germany protest against nuclear weapons and nuclear energy was one of the core issues of the Green Party for the last 40 years. Restarting or extending the lifetime of existing plants would be political suicide for the current government.

If they're smart they can build support for modern designs, probably small nuclear, as long as they can convince their voter base that the risk of accidents and the problem of waste disposal are much smaller than with the outdated plants they helped close down.

From an economic perspective it's a hard sell compared to solar and wind plus storage, but with the resistance to new windfarms by NIMBYs you can probably justify some subsidies. The timescales involved are still a problem though.

> In Germany protest against nuclear weapons and nuclear energy was one of the core issues of the Green Party for the last 40 years.

Yes, "Green" Parties are a blight on the political landscape everywhere.

> Restarting or extending the lifetime of existing plants would be political suicide for the current government.

Well, for the bottom of the current "traffic-light" coalition, anyway... (We can but hope.)

Germany will kill its economy if they rely solely on so called "green energy".

> a lot of gas gets used for heating - nuclear isn't useful there.

Erm, no, that's just not true. Ironically, the best counter to that is... Russia, which successfully supplies a few million with extremely cheap hot water.

Maybe not with the existing ones. Otherwise a lazy search for nuclear district heat is contradicting you:

[1] https://www.nucnet.org/news/operation-begins-of-qinshan-nucl...

[2] http://www.chinadaily.com.cn/a/202112/22/WS61c27b44a310cdd39...

[3] https://www.world-nuclear-news.org/Articles/Chinese-nuclear-...

[4] https://www.neimagazine.com/news/newschinese-nuclear-compani...

Heat pumps are a thing. Also the problem with wind and pv is insufficient storage. We need additional storage more than additional wind/pv.

> Germany most of all now has to correct the mistakes by the previous government and very quickly has to push for building up more wind and solar capacity.

If any of what you say is true at all, how did France survive for so long on nuclear power?

See https://www.bp.com/content/dam/bp/business-sites/en/global/c...

France uses 40.7 billion cubic meters of gas (0.6 per capita), while Germany uses 86.5 (1.03 per capita). Given that France has a warmer climate the difference is not all that big. France does not survive on nuclear power alone.

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