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Danube's record low levels force shutdown of Hungary's only nuclear plant (bbc.com)
Triesault 36 minutes ago [-]
I wonder if any new hunger stones have been found since the Danube's wafer level reached this new record low.

https://en.wikipedia.org/wiki/Hunger_stone

comrade1234 11 hours ago [-]
Here in Switzerland during some heatwaves they have to shut down nuclear plants too because the river water is too warm and adding warm water to it would kill the fish.
petre 10 hours ago [-]
Would a cooling pond with controlled discharge into the river maybe mitigate this problem? One could also cycle the water from the cooling pond through the plant's cooling loop. The worse that could happen is evaporate the water from the cooling pond which is gets replaced with new water (sans fish) from the river.
topspin 2 hours ago [-]
> Would a cooling pond with controlled discharge...

There are any number of methods of dealing with this. Using natural bodies of water is a lower cost (thus highly popular) method of sinking heat. Palo Verde has been operating 3 large reactors in the Sonoran Desert in Arizona since the 1970s. There is no reason in engineering or physics that a power reactor must be highly sensitive to any particular lake, river or ocean's temperature. This is strictly about money, being cheaper to rely on a big "free" heatsink, and leaving too little margin for changing conditions.

wcoenen 2 hours ago [-]
Nuclear plants can run with those hyperboloid cooling towers as the sink for waste heat. They are just a lot more expensive to build, run and maintain compared to using river water.
Choco31415 3 hours ago [-]
There's plenty of work happening with adapting non evaporative cooling loops for data centers. Maybe that can be applied here too, even if to mitigate some of the cooling needed?
Retric 37 minutes ago [-]
Data centers can afford to spend way more per kWh of heat discharged. Nuclear needs to dump 3+kWh of heat per kWh of electricity generated.
2 hours ago [-]
downrightmike 2 hours ago [-]
making modern websites not 100's of megabytes heavy would go a long way
delecti 28 minutes ago [-]
FWIW, this one was only about 5 MB.
number6 11 hours ago [-]
And it's not cold enough to cool the reactor
masklinn 11 hours ago [-]
The reactor absolutely is not going to care, it’s the tertiary cooling circuit cooling for the steam turbines, it will have cooked off everything downstream long before it’s an issue.

This is entirely an ecological and safety concern.

dredmorbius 5 hours ago [-]
The principle cooling mechanism is vapourisation.

The heat of vapourisation for water, converting liquid to steam, is 40.66 kJ/mol, or 2257 J/g. It takes a lot of energy to boil off water.[1]

That compares with the latent heat of liquid water, the energy required to heat one unit of water by one degree, which is 4.2 J/g*K (where K is the delta temperature in Kelvin).

Raising the temperature of input by, say, 10 degrees, would only reduce the cooling factor by less than 2%.

________________________________

Notes:

1. Which is why live steam is so dangerous. Steam condensing will release a huge amount of thermal energy, making steam burns especially harmful.

seszett 11 hours ago [-]
No that's never the problem, even 40°C intake is cool enough to cool a reactor, it's all just a question of returned water temperature that can be harmful to a river if too high (generally the limit in Europe is set to 30°C).
Retric 36 minutes ago [-]
As long as it’s designed for those temperatures everything is fine, but efficiency still suffers.
masklinn 8 hours ago [-]
It can vary by the river too (e.g. I remember Switzerland pulling back a reactor around 25 intake), and iirc there’s an absolute limit on the outflow (you don’t want to boil alive the stuff just off of the plant) and a relative one a bit downstream (you can’t heat the river to 20 when it’s freezing).

These heatwaves reduce the margin from both directions, a hotter intake means you have less margin on the outflow, and the lower flow rate means there’s less water to dilute that outflow. And apparently for that specific plant there’s also the water level not even reaching the intake.

shakow 10 hours ago [-]
Absolutely wrong. A difference of a couple degrees is not going to hamper cooling a reactor that is running at many hundred degrees.

Just imagine what it would spell for your car otherwise.

ZeroGravitas 9 hours ago [-]
I think both nuclear steam and car engines are affected by high ambient temp, gas and coal engines too.

That is after all why they bring in water or air to car radiators, to cool them.

Probably only a single percent or so for a few degrees change though.

shakow 49 minutes ago [-]
Convection cooling efficiency is mostly dictated by the delta in temperature between the hot and cold source. Coolant temperature in the core is in the 300C ballpark. So the river going from 20 to 30C is roughly a 0.3% change in cooling efficiency.

For your car, coolant temperature is typically in the 80-90C range. So the same change in external temperature would be a loss of ~10% of cooling efficiency. Still, cars have no issue running in 30C temps, and IME you have to go up to 45 to really need specialized cars.

So if you car can swallow 40C and >10% efficiency loss without a sweat, a NPP will have 0 issue using 30C water to cool their cores.

voakbasda 6 hours ago [-]
Begs the question: coul reactors use radiative air cooling? Channel the water through a huge radiator and transfer the heat to the air
HPsquared 3 hours ago [-]
The temperatures aren't high enough to do that (or air cooling) efficiently enough. Some experimental designs for high temperature operation would have that as a possibility (e.g. molten salt reactor designs). I think a Chinese research project is looking into air cooling for nuclear power in dry regions.
namibj 51 minutes ago [-]
There's also the potential of co-locating non-evaporative cooling with CO2-scrubbing using a strong KOH solution in the big cooling towers and regenerating the hydroxide with calcium hydroxide (regular process done in kraft process paper mills, though they use NaOH with slightly favoured properties over KOH). KOH is very hygroscopic; it does not have to be humid for a barely-still-liquid solution to actually dehumidify in the process.

Or, if that's too much effort for them, use e.g. LiBr or other such atmospherically-stable salt that can maintain humdity equilibrium with dry ambient air.

The reason for even involving a water-based solution at all is because you can spray it or at least run it over dense corrugation (sheets alternating orientation, but overall with the channels roughly pointed upwards) "packed beds" with free contact between the coolant and the air, instead of having to maintain a barrier layer between the two (typical car/computer radiators, but also AC coils), which notably saves you from even a potential for a there-required barrier layer to leak and from having to clean such a barrier layer. If you make the corrugations large enough and have some simple mesh filters in the intake path that you just roughly shake/rinse/blow/brush off every once in a while, you can prevent particles larger than a rice grain from getting to the coolant in the first place and wash/rinse all the sand grain and smaller dust particles down into the coolant sump where their densities are far better matched (than air vs. dust) and volume flow is much easier to handle/filter.

The big part of these is still that they don't require active fan ventilation to cool radiators, which would be a substantial increase in critical electrical power needed after a SCRAM to keep the core from melting down; vs. the passive evaporative cooling towers and the KOH/LiBr non-humidifying variant I mentioned.

masklinn 6 hours ago [-]
Not really, a large reactor is way too power dense. An EPR reactor has a thermal output of 4.6GW. And the tertiary is cooling steam turbines so it's below boiling, you'd need something like 10 sqkm worth of surface, per reactor, with an environment cool enough that this could actually radiate.

Even using industrial air-cooling design you'd need on the order of a million sqm or two (for reference a good quality computer heatsink is about a third of a square meter worth of fins)

philipkglass 3 hours ago [-]
The German THTR-300 reactor operated with air cooling:

https://en.wikipedia.org/wiki/THTR-300

But it was admittedly a huge cooling system for a reactor that only produced 750 megawatts of thermal energy.

VLM 3 hours ago [-]
OP is correct, the people making fun of OP don't have an engineering background.

The pressure of a condenser at 90F (hot summer day) is about 1/20th of an atmosphere and ... pretty obviously the pressure of a condenser at 212F is about one atmosphere. You can't just arbitrarily decide to change the low pressure side of a turbine like that, its not going to turn out well. You could, in theory, design an entire thermal plant coolant loop to deal with the condenser running at 1 atm instead of 1/20th atm but most will not.

There are also heat flow rate issues where the higher the delta V the higher the watts. Regardless of condenser pressure issue above, if a heat exchanger can pull 1 MW across a 150 degree delta-V then if you run the cold side much warmer at only 15 degrees delta V it can only "pull" 0.1 MW of heat. Its surface area doesn't magically get bigger LOL. Remember that for every watt of electricity you get to dump around three watts of thermal heat. If you lose 9 MW of cooling power you lose 3 MW of output electrical power. You have to move more heat than non-engineers expect, to generate electricity.

Its a simplification, but for various reasons they like to design the hot side as hot as possible, so if you lose 100F of cooling you can't keep the same power output and simply run the hot side 100F hotter than normal and keep the same flow rate. Absolutely nothing good will come from overheating it like that.

You could engineer a thermal plant (thermal as in coal, nuclear, burning recyclables and biowaste, anything to make steam) that runs at an ideal hot side of 212F and let the hot side literally boil water in a pool. However, they don't make plants like that IRL and trying to force it under those conditions would turn out very bad... The first thing that comes to mind is gunk buildup and higher corrosion rates. Steel (generically speaking) corrodes in water about twice as fast per every 20C increase, so turning a cold water plant into a water boiler would to first approximation cause about a year's worth extra corrosion per month. Could be designed around, but I would not want to cowboy a nuke and just try it. Some of those parts are very expensive; even if you can safely run the plant and replace the corroded parts at a substantially accelerated rate, the cost of power due to corroding the cold side parts might make the power too expensive even if its "safe enough", making it cheaper to just shut down. Moving large amounts of water (or air) is extremely expensive, both capex and opex, so an additional 10x higher once in awhile here and there could be a lot of money...

Luc 11 hours ago [-]
Of course a 1960's design isn't adapted to current weather conditions. That doesn't mean the whole technology is useless, like so many commenters imply.

Any new build can and will include cooling adapted to hotter conditions.

riffraff 1 hours ago [-]
The one that shut down in Romania is a CANDU, built in the 80s.
one33seven 7 hours ago [-]
There's a nuclear reaction in the sky beaming free energy to us, let's just use that
chpatrick 2 hours ago [-]
Hungary is already using that (today we were 90% carbon-free thanks to solar), the problem is what to do when it gets dark.
dofm 2 hours ago [-]
"the problem is what to do when it gets dark"

Batteries (or pumped storage hydro, which is more like a gravity-driven capacitor)

riffraff 1 hours ago [-]
Hungary is flat as hell, there's nowhere to build enough hydro storage.

But yeah batteries would be nice.

JeremyNT 47 minutes ago [-]
You can do low(er) head pumped hydro storage [0]

[0] https://en.wikipedia.org/wiki/Ludington_Pumped_Storage_Power...

dofm 1 hours ago [-]
AFAIK the mountains are about as high as Wales? It looks like there's a 600MW storage scheme in the planning stages. That's about a third of the capacity of Wales's largest system (which is the biggest in Europe) and about twice the capacity of the second system.

It's a meaningful contribution I would have thought.

ccozan 2 hours ago [-]
Batteries?

Starting this year, in Romania you cannot put new PV capacity online without the storage for it, is mandatory. Possibly for existing ones, but I am not sure.

chpatrick 2 hours ago [-]
They're being installed but it's going to take a while.
imoverclocked 2 hours ago [-]
Mechanical ones so we aren’t left with a waste disaster in 10-20 years?
exploderate 10 hours ago [-]
It's not matter of "can", it's a matter of "how much does it cost?" and "who pays for that?".
expedition32 10 hours ago [-]
Precisely why the Netherlands does not have nuclear power plants. Cheap coal. Cheap oil. Cheap gas. And now cheap wind and solar.

They just absolutely cannot math the math which leaves ideology and this ain't France.

cucumber3732842 10 hours ago [-]
[flagged]
roenxi 9 hours ago [-]
You're probably going to struggle to come up with a motive for that behaviour. It is much more likely that they simply aren't very thoughtful. Complex webs of deception in a public argument are certainly possible, but it generally relies on some group having a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.
one33seven 7 hours ago [-]
> a clear financial incentive to misdirect. That doesn't exist in the nuclear debate.

It's very obviously not in the interests of "big fossile" to go either solar or nuclear.

cucumber3732842 7 hours ago [-]
>You're probably going to struggle to come up with a motive for that behaviour.

No, I'm not. Not in the slightest.

Number in top right go up. Monkey brain feel goooooood when that happen. Monkey brain keep doing behavior that make that happen.

> It is much more likely that they simply aren't very thoughtful.

They're plenty thoughtful. They'll contrive all sorts of arcane logic, plausibly deniable lies and witty turns of phrase (some of which are quite impressive).

What they're not is self aware (the dishonesty is a byproduct of that).

> Complex webs of deception

Those are possible but I don't think that's what's happening here.

> but it generally relies on some group having a clear financial incentive to misdirect.

Internet fanboys work for free. They have no financial incentive. Therefore we fall back to the monkey brain incentive.

pepperoni_pizza 11 hours ago [-]
You can totally retrofit existing nuclear power plants for closed loop cooling. I'm not sure what the cost would be, though, but it might be worth doing.
Elfener 11 hours ago [-]
I've read that in the case of Paks a retrofit doesn't make sense because the entire thing is so old and needs to be rebuilt anyway.

However, hopefully, they change the plans for (stalled project) Paks 2, because that would've used the same cooling system as the first one.

10 hours ago [-]
Pay08 3 hours ago [-]
I believe there was also a planned much cheaper retrofit to use pumps to increase force to necessary levels but it was scrapped.
moffkalast 11 hours ago [-]
Is it economically viable to run though? Natural draft towers or direct body of water cooling is used almost universally since it doesn't take any extra power. A large chunk of the powerplant's output would be running heat pump compressors to stop itself from exploding.
wongarsu 11 hours ago [-]
Fully closed loop is probably not viable. But I suspect that's not the extreme GP might have meant.

If for the sake or discussion we simplify cooling to four options:

1: just passing river water through a heat exchanger for cooling

2: ingesting river water, using it for cooling, then passing it through a cooling tower before returning it to the river

3: pass the water output from the cooling tower directly back in the cooling loop, only ingest enough water to replace evaporation

4: fully closed loop via direct heat exchange with air

Then 4 is not very viable. But a lot of nuclear plants are stuck at 1 or 2, and each step up the ladder would allow them to operate in worse conditions. This one seems to be at version one

noduerme 11 hours ago [-]
How do these things, whose sole purpose is to turn heat into electricity, end up with so much extra heat that it takes more energy than they produce to disperse it? Can't the excess heat in a closed loop system be captured and used to power the cooling? Sorry, maybe this is a stupid question.
dredmorbius 5 hours ago [-]
Thermodynamics, specifically the Carnot Cycle.

Heat engines do turn heat into mechanical energy (motion).

What they don't do is do this with infinite efficiency.

In practice, Carnot engines (heat engines) tend to operate at efficiencies between about 20 to 50%, with an average close to 30% percent. This means that most thermal electrical generation produces roughly three times as much heat as it does electricity. This applies across thermal mechanisms: diesel generators, gas turbines, coal-fired steam, and nuclear-powered steam plants.

There's some room for increased efficiencies, and multi-pass systems, or systems with incorporated thermal applications (district space heat, industrial heat, food preparation) can achieve higher net efficiencies, though I believe the peak is around 60%, and that is rarely achieved.

The other parts of the generating cycle are far more efficient. Generators typically operate well above 90% efficiency (mechanical energy in to electrical energy out), and distribution typically sees about 6% losses.

But that first thermal step costs a lot. There's no such thing as a free lunch.

<https://en.wikipedia.org/wiki/Carnot_cycle>

throwway120385 3 hours ago [-]
"Heat" is really entropy gain, and so in order to do useful work you have to increase the entropy of the system to higher and higher quantities. If you want to move entropy from one closed system to another(to cool one system down) then you must emplace even more entropy in the one system than you removed from the other because you must spend entropy(generate heat) in order to force a change in the state of the other system. It's a fundamental law of physics. You cannot reduce the entropy of the universe by any means.

This is true whether you use an engine, a river, or a solid-state fully electronic device. Even humans must obey this law, and indeed there has to be some air movement for us to cool down using our sweat, and interrupting or changing that air movement costs energy and therefore increases entropy somewhere.

Tade0 10 hours ago [-]
The heat is spread out to a much larger volume.

Heat engines are most efficient when the temperature difference between the hot and cold side is high, so you need to keep it that way to extract energy.

A nuclear power plant achieves this by converting extreme heat from a small, but very angry rock to a huge lake of slightly warmer water.

There exist reactor designs which operate at higher temperatures, thus increasing efficiency, but they're complicated as everything needs to be more heat-resistant.

petre 10 hours ago [-]
5. scrap 1..4 and build a gas cooled reactor instead.

https://en.wikipedia.org/wiki/HTR-PM

emsign 11 hours ago [-]
First of all you can't retrofit every npp with that, it's a lie. And eve; if you could, you are correct, it's financially not viable. Renewable energy is always the cheaper option by far.
VLM 3 hours ago [-]
I find it interesting the discussion here is entirely about water temperature whereas the shutdown is entirely about NPSH.

True there is a small different in NPSH pump limit of hot summer water vs cold winter water, but not as much as you'd think.

Its not that the intake pipes are hanging out in the breeze above water; most pumps are designed not to cavitate at a certain input pressure (often pretty low) and I was bored enough to look it up and when the river is 134 cm below reference at this site, the pumps will be very unhappy long term if you keep sucking water in. They'll keep running, at a reduced rate, but cavitation will cause serious issues. At some sites, perhaps not this site, filtration systems (grates and stuff) on the input are designed for a certain ideal pressure and ideal flow rate, so that can also be a problem.

Thermal limits are also very arbitrary and designed to a financial limit. Most plants worldwide are limited to a delta V, I suppose there could exist an environmental law that limits to an arbitrary fixed temp. Normally if 10 gallons/sec heats up 10 degrees, then 100 gallons/sec would only heat 1 degree. But it would cost 10x as much and only be needed a couple days/year in the driest summers, so a tradeoff point, well chosen or not, was selected. Most absolute limits are utterly ridiculous like 90F. The only long term way to maintain a river at or above 90F is an air dew point of 90F and most people will be dead by then. I find it improbable the water temp is too high, everyone without air conditioning would already be dead if the dew point were substantially over 90F. You could probably "cook" a small lake or dam area with a nuclear plant into something like a giant hot tub, but not a free flowing river.

Looking at the mass media coverage, its mostly pictures and discussion of low water levels (the true cause) followed by journalist and consumer discussion about water temps, there is no meeting of the minds between the engineers and the general public and AI and journalists.

If for whatever weird reason, river levels were low in the winter, low NPSH at the pumps would shut it down just as effectively at a water temperature of 1 C. Large industrial water pumps react extremely poorly to low input pressure.

vrganj 13 hours ago [-]
This is happening all across Europe right now - Romania, France too.

https://www.euronews.com/business/2026/07/13/france-shuts-do...

https://www.reuters.com/business/energy/hungarys-paks-nuclea...

We keep having folks here argue that nuclear, not renewables are the path to take to get rid of fossil fuels. I have strong doubts - it feels like that doesn't account for the sad realities of climate change.

cinntaile 12 hours ago [-]
People arguing for one alternative over the other are usually politically motivated. I feel like you are doing the same. Sometimes nuclear is a good fit, sometimes renewables is a good fit, sometimes fossil fuels are a good fit. Most of the time a mix is the best fit. It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible. All these systems are then built using assumptions, sometimes those assumptions no longer make sense after a certain period of time and sometimes you just temporarily or permanently have to adapt to the changes in the environment. This is an unusual but expected scenario for the nuclear plants along the Danube.
seszett 10 hours ago [-]
> sometimes fossil fuels are a good fit

There is simply NO safe level of fossil fuel use.

ben_w 10 hours ago [-]
Disagree, it's just that the safe level is around 0.1% of current use (though I don't just mean use of fossil fuels for electricity, I mean *everything*).
danw1979 10 hours ago [-]
There’s applications that we still have no alternative for though - e.g. aviation - so we’ll have to accept the burning of hydrocarbons there.

Not fossil hydrocarbons forever, of course, but synthetic kerosene might be a thing soon enough.

cinntaile 9 hours ago [-]
I don't know what you mean with "no safe level of fossil fuel use". It doesn't mean anything without contextualizing that statement.
paganel 11 hours ago [-]
Everyone is politically motivated on this subject, and that's a good thing, because this is a political decision by default, where the "political" is comprised of is, the voting citizens. We can't let decisions like these be taken by unelected technocrats alone.
gib444 11 hours ago [-]
I'm not filled with joy about my chav ("redneck") neighbours weighing in on nuclear vs solar and climate change and national and international energy markets and power distribution...

I don't have a clue either. Don't ask for my vote on how to power a country. Take my taxes and use them to listen to experts

dudefeliciano 10 hours ago [-]
Plot twist, the experts are lobbyists and they convince our politicians to start fracking and massively increase the use of "clean coal"
11 hours ago [-]
cucumber3732842 10 hours ago [-]
>and that's a good thing, because this is a political decision by default,

Why is it a good thing that everyone and their brother seeks to apply state violence to micromanage what should be a fairly arcane technical issue?

>We can't let decisions like these be taken by unelected technocrats alone.

Do you feel the same way about topics where your opinion differs substantially from the local majority?

andor 9 hours ago [-]
Very few things are purely technical decisions. In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way). One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

Edit: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals, from your dinner table and your company Slack to democratic institutions.

roenxi 9 hours ago [-]
> One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

I almost hesitate to ask, do you think that is the centralised or decentralised option?

And, more directly, that is a bad theory. The billionaires will make money either way. It doesn't make a lot of difference to them as a class. They'll have an inclination to the cheaper form of energy because more energy -> more economy -> more money for them.

cucumber3732842 8 hours ago [-]
>In this case, it’s about centralized vs. distributed electricity generation (or freedom vs. dependence if you want to state it that way).

The venn diagram between people who act like renewables are "freeing" (which make no mistake, they absolutely could be) and the people who advocate nonstop for government management of how they are deployed is too close to a circle for me to take such commentary seriously.

>One of these options makes it much easier for the billionaire class to continue extracting money out of the people.

Ah, yes, billionares. Famous for not getting a cut when I buy a plug in solar panel from my preferred e-commerce site or big box store. /s

The billionares have their money in everything. They get a cut of everything. You're just changing who gets the cut. And even if no billionaire is getting a cut, a publicly traded/owned investment bank or other corporate interest that would replace them is not really any less evil.

>: I don’t understand how you get from „political decision“ to „state violence“. Politics are at play at all levels of civilization where actors have different goals,

By not gaslighting myself into thinking politics is anything other than the process of deciding where, when and how state violence is applied.

What backs up all those decisions other than credible threat of violence?

dudefeliciano 38 minutes ago [-]
> people who act like renewables are "freeing" ... and the people who advocate nonstop for government management

Where did the person you are replying to even hint at that? I think this may be your own prejudice spilling out here.

> The billionares have their money in everything. They get a cut of everything. You're just changing who gets the cut.

Oh ok, I guess let's just accept this as is forever. Any attempt to try to improve this situation is futile and stupid (for example, as said, making it more difficult for them)

>What backs up all those decisions other than credible threat of violence?

I don't know, do you only act in fear of the threat of violence from the state? In democracies politicians are legitimized by their voters, what you are describing sounds more like an autocracy.

stavros 11 hours ago [-]
Agreed, whenever I hear someone say "we need more/less nuclear and less/more solar/wind", I hear "let's burn more fossil fuels while we uselessly split hairs".
otherme123 16 minutes ago [-]
Unless the scenario is totally different where you live, pro-nuclears are mainly "we need more nuclear, less rerewables, don't care about fossils, just guaranteed production", while pro-renewables are mainly "we need more renewables, less or no fossils and as few nuclear as possible".

If someone is getting wiped from the mix because of renewables, it is coal and fuel, not nuclear.

dudefeliciano 10 hours ago [-]
The point they are making is that climate change will further push these conditions, so are we willing to build more nuclear power plants, knowing that by the time they are ready to go online this problem will be worse? Or better to invest in renewables which can be implemented today and will alleviate this problem? A mix of both with heavy majority of renewables and nuclear/fossil only to guarantee baseloads seems like the best idea to me.
vrganj 12 hours ago [-]
I'm not really opposed to nuclear power politically. I just think it's a non-starter given the much higher cost, complexity of buildout and lack of reliability.
deepsummer 11 hours ago [-]
In countries with dark winters and without enough hydro power, the only reliable alternative are fossil fuels...
comrade1234 11 hours ago [-]
Iceland has no nuclear power plants.
defrost 11 hours ago [-]
Iceland is a small area, small population outlier literally sitting on two plates rubbing up against each other and a relative excess of active volcanism and large lava fields.

  About 85 percent of the total primary energy supply in Iceland is derived from domestically produced renewable energy sources. Use of abundant hydroelectric and geothermal power has made Iceland the world's largest electricity producer per capita.
~ https://en.wikipedia.org/wiki/Iceland

What works for Iceland works in few other places to the same degree (New Zealand, Yellowstone, places with thin crust and feisty caldera's).

number6 11 hours ago [-]
Germany also has potential for 85% geothermal energy.

There are some interesting spots here but it's generally enough through the country to do it everywhere.

Munich gets quite a lot of it's energy from geothermal sources

deepsummer 11 hours ago [-]
Countries like UK, Ireland, Germany, Danmark, Netherland, Poland also have dark winters. Solar in winter is only about a fifth of production in summer months.

Iceland has geothermal, which is amazing, but won't help central Europe.

ben_w 10 hours ago [-]
Those places also have a huge wind resource in the form of the North Sea, for Ireland whatever the other bits of that submerged continental shelf are called, and for Poland the Baltic: https://globalwindatlas.info/en/

This is important because wind season anti-correlates with PV season.

Plus, it's not like north-south power lines are beyond the wit of mankind. The US western interconnection includes both Canada and Mexico: https://en.wikipedia.org/wiki/File:NERC-map-en.svg

deepsummer 10 hours ago [-]
Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further. Storage in the required dimensions is an unsolved problem.
ben_w 9 hours ago [-]
> Yet there are whole weeks practically without wind in winter. And most climate models estimate that global warming reduces wind further.

Not for the combination of [continent-wide, offshore, the Atlantic coast].

The Atlantic continental shelf isn't correlated with the Baltic.

Offshore Dunkelflaute is much shorter than on-shore.

> Storage in the required dimensions is an unsolved problem.

Also false. The required quantities even of batteries is comparable to electrification of road transport.

Also, independently of batteries, hydro plants come in two flavours that people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty, and just the currently and soon-to-be closed coal mines in the EU can be converted to around 13 TWh of pumped storage: https://gfzpublic.gfz.de/rest/items/item_5038282_1/component...

And it's not like we can't dig more holes if we wanted to, we dig holes to get out rocks even though rocks are one of the cheapest things you can buy.

deepsummer 8 hours ago [-]
> The Atlantic continental shelf isn't correlated with the Baltic.

How do you transmit the power? Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?

> Offshore Dunkelflaute is much shorter than on-shore.

That reduces the storage requirements a bit, but there is not nearly enough offshore. And offshore is expensive. That's why it's getting harder to find investors.

> The required quantities even of batteries is comparable to electrification of road transport.

That doesn't prove it's possible, but makes it even harder to get the required quantities.

> hydro plants come in two flavours that people often mix up: generation, and storage

Hydro requires the right geography. Is there any potential for hydro left in central Europe?

> EU can be converted to around 13 TWh of pumped storage

That would be a good amount of storage. But has this ever been tried? I would guess that's quite dangerous: https://www.youtube.com/watch?v=LseK5gp66u8

deepsummer 7 hours ago [-]
Max comment nesting reached. Instead of going through your response one by one, let me just say one thing: the premise and promise of the whole energy transition are based on studies that completely underestimated the physical and engineering challenges in practice. That's why we are where we are. Energy costs have gone up; CO2 emissions have not. I wouldn't believe any study before it has been implemented at scale, at least in a region or small country.
ben_w 7 hours ago [-]
> How do you transmit the power?

The usual way.

> Do the countries on the Atlantic even want wind power, set up the transmission lines, and pay for it?

They can sell the power, you know. This already happens.

> That reduces the storage requirements a bit, but there is not nearly enough offshore.

It more than covers it.

Even a Dunkelflaute period is reduced, not zero, output. Those seas are huge, and the normal wind there is fast; even on a continental-shelf-spanning Dunkelflaute (much rarer than "just Germany and Poland"), the capacity in those waters *even with that reduction* is more than EU demand just by itself, which in practice means "not building as much as possible".

> And offshore is expensive. That's why it's getting harder to find investors.

Compared to onshore wind. But even offshore wind is cheaper than new-build nuclear, coal, and has strong overlap with new CCGT.

Even then, it's not hard to find investors: the US went as far as banning it because the investors were actually happy to invest.

The limitation on investors right now is that we're transitioning faster than any previous energy transition before, while also having other things to also invest in. It's like how big tech in the US is running out of people to get money from to spend on data centres, the limit isn't actually building them, it's how fast they're getting built when your answer to "how many would you like to order?" is "yes".

> That doesn't prove it's possible, but makes it even harder to get the required quantities.

The fact that EVs are for sale, however, does.

> Hydro requires the right geography. Is there any potential for hydro left in central Europe?

I thought you might say something like that, *which is why I literally wrote what I wrote*:

  people often mix up: generation, and storage. Of these, only generation requires an associated upstream supply and watershed; storage can be done with a hole in the ground, of which there are plenty
And then linked you to a document, with a quote from that document, about using coal mines. The document you replied to with doubts, supports the conclusion you've just denied.

Also, I already saw all of Tom Scott's videos when they were new. As per the document:

   Finally, the realisable potential includes projects that are not only technically and economically feasible but also aligned with regulatory, environmental, social and implementation timelines, facilitating their implementation within short to medium time frame.
frm88 9 hours ago [-]
Storage in the required dimensions is an unsolved problem.

No, it's not. Decommissioned nuclear plant infrastructure used as massive battery storage.

https://gesi-deutschland.de/en/gesi-project-presented-in-gro...

deepsummer 8 hours ago [-]
870 MWh? It would take about 500 of them to make it through a 1-2 week dunkelflaute.
ben_w 8 hours ago [-]
Why do you think that's a criticism?

  The following table shows that in total 2264 installations have been identified in the EU ETS to be power plants, which have reported emissions in at least one year since 2005. The fuel of 1440 power plants have been identified. Of this there are 124 lignite power plants, 284 hard coal power plants and 2  power plants using blast furnace gas. There are 57 power plants using oil products. The majority of the plants uses natural gas (858 plants). About 824 plants have not been matched to a fuel yet.
- page 8, https://www.eionet.europa.eu/etcs/etc-cme/products/etc-cme-r...
oblio 11 hours ago [-]
Wind + storage, geothermal.
deepsummer 11 hours ago [-]
Storage of energy in the dimensions required for weeks with almost no wind is an unsolved problem. Right now, we can't store enough to make it through a single night without using fossil fuels. Most countries don't even have the capacity to store the energy for a single hour.
RandomLensman 11 hours ago [-]
As we can store fossil fuels for weeks of demand, we can store the required energy in chemical form, no? Germany has huge natural gas storage, for ezample.
deepsummer 10 hours ago [-]
If you mean hydrogen, this video explains the issues better than I can: https://www.youtube.com/watch?v=Zklo4Z1SqkE
RandomLensman 10 hours ago [-]
Doesn't need to be hydrogen - plenty of possible substances that could be used as storage (might not even need to be gaseous for some applications).
emsign 11 hours ago [-]
Geothermal and storage is worth investing in, investing in nuclear is not. NPPs are simply too expensive and you won't find investors unless you heavily subsidize it with tax money. Only compnies willing to invest in NPPs are those with virtually free money: the handful of AI big tech giants.
deepsummer 10 hours ago [-]
How can you be sure of that before even having a practical and proven solution for the required scale of storage?
ben_w 8 hours ago [-]
We have proven solutions.

We're building the factories to make them as fast as we can find investors with money to spend on them, because they're already cheaper than fossil fuels which are themselves cheaper than nuclear.

ThePowerOfFuet 11 hours ago [-]
>sometimes fossil fuels are a good fit.

Oh come on.

Krasnol 9 hours ago [-]
> People arguing for one alternative over the other are usually politically motivated.

If you can spend a Dollar only once, you might end up with renewables. People can be economically motivated too. No reason to draw politics in an already heated discussion.

cinntaile 8 hours ago [-]
> It depends on what you are optimizing for and what is geographically, (geo)politically and economically possible.

I mentioned all of this in my message. What was unclear about it or did you perhaps not read past the first sentence?

themaninthedark 2 hours ago [-]
I have not seen anyone arguing only nuclear to get rid of fossil fuels, what I see is people arguing that we need nuclear to supplement renewables to remove fossil fuel and the other side saying renewables and batteries(and maybe the occasional gas peaker plant or two...) or bust.
eecc 11 hours ago [-]
It’s the second of third year in a row that this happens.

At some point it will be the new normal.

Cthulhu_ 11 hours ago [-]
It can be, but you need water, just like for solar you need sunlight and storage and for wind power you need, well, wind. Coal and gas rely on natural resources, which can be disrupted through geopolitical tension, like Russia's gas supplies into Europe getting cut off / sanctioned.

Every power source has their tradeoffs, and I don't think anyone is denying that.

What I do think is that people are making up arguments or statements that Other People have and call them out on it.

xinayder 9 hours ago [-]
High temperatures also severely affect solar panel efficiency.
stefan_ 11 hours ago [-]
This is a technical problem with technical solutions. You can just fix things, you don't need to throw out 30% of your power generation to pay billions for climate change vagueposting.
Cthulhu_ 11 hours ago [-]
Kind of? I'm sure you can change a nuclear power plant so it doesn't rely on river or sea water but that's not something that can be done overnight.

Restoring river water levels can't be done through technical solutions though, they rely on the weather and we can't control that. The European river levels are largely influenced by inland rain, snowfall, and glacier forming/melting; snowfall and rain has been meagre this year, glaciers have been melting and receding for decades now.

emsign 11 hours ago [-]
Electricity costs by nuclear power is heavily subsidized by tax money in France, so the French are paying the higher costs anyway. Just saying. Maybe there's a technical solution involving nuclear but it's really expensive compared to the much cheaper technical solution: renewable energy.
flr03 11 hours ago [-]
Different reasons though, France has nothing to do with water level or availability. It's for environment protection.
emsign 11 hours ago [-]
Not true at all. It's both in France and increasingly because the rivers run dry in the summer. Besides killing rivers for electricity and for "saving CO2" is as stupid as burning coal to keep HVACs running becauae the summers are getting hotter and hotter each year.
Ethan312 13 hours ago [-]
A nuclear plant being forced offline by low river levels is a striking reminder that even low-carbon energy depends on climate-resilient infrastructure. How many plants across Europe face the same cooling-water risk?
raverbashing 11 hours ago [-]
If only there was a power source that would excel during sunny and warm days, huh

Then we could stop the nuclear plants when needed for cooling and maintenance

chpatrick 2 hours ago [-]
Hungary actually has a ton of solar, video from today: https://www.youtube.com/watch?v=HqpTN5PZLow

The problem is we don't have enough storage to use it after dark.

seszett 11 hours ago [-]
> we could stop the nuclear plants when needed for cooling

Well that's exactly what they did thanks to solar power provided by the rest of the grid, so your snark seems rather unwarranted.

josefritzishere 7 hours ago [-]
Desertification is next.
measurablefunc 3 hours ago [-]
It's now.
emsign 11 hours ago [-]
This is what nuclear power enthusists like to ignore when they talk about nuclear power being a solution to energy and climate change.
bsza 10 hours ago [-]
Worth mentioning we also had to shut down the largest block in our largest gas power plant on the exact same day due to an unrelated error.

https://www.dert.hu/hu/sajtoszoba/0/141 (in Hungarian, couldn't find an English source)

Cthulhu_ 11 hours ago [-]
Is that a fact or are you just trying to spark a debate?
mertbio 11 hours ago [-]
They also constantly criticise Germany and its nuclear power plant closures, linking almost every negative news story about the country to this issue. It seems they’re completely unaware of the potential consequences of operating a nuclear power plant.
sajithdilshan 3 hours ago [-]
A lot of energy crisis in Germany is due to the closure of their power plants. Just like any other infrastructure, nuclear power plants needs to be modernised over the time and Hungary didn’t do that. It’s not the fault of nuclear technology, but lack of management in Hungary’s case
fylo 11 hours ago [-]
Every power source has trade offs, bud. They call solar renewable, but in fact panels have a shelf life, and take valuable finite resources and energy to manufacture. This is what climate change activists like to ignore /s
ck2 3 hours ago [-]
Thorium Reactors are the future, much more controllable and "fails safe-r"

they also can "burn" nuclear waste (spent fuel from water reactors)

* https://www.youtube.com/watch?v=ElulEJruhRQ

11 hours ago [-]
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