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We're building one nuclear reactor in the UK and it's so expensive it has been dubbed "the most expensive electricity on the planet" and has almost bankrupted the French energy company which is constructing it. It's also taking many years longer than planned to finish it. If your plan happened, "cheap energy from an expensive source" means low profit and low return for the investors of the power plant. USA is not faring much better in the 'showing it can still build public nuclear power plants' stakes, or in the building large public construction projects quickly and cheaply stakes.

See my previous large comments with details on pricing, build times, cost increases in nuclear power, before dismissing this as a throwaway comment:

https://news.ycombinator.com/item?id=28892582

https://news.ycombinator.com/item?id=28890546

tangential: https://news.ycombinator.com/item?id=30636890

A FUCKTON of nuclear plants are not coming soon enough to save us.

One-off projects are usually incredibly expensive because you have to make everything custom. I don't think this argument "scaling up must be expensive because our one-off project is expensive" goes. Doesn't one usually expect to pay 5-10× as much to have something made custom as opposed to a common product?

There's on the order of 500 of them in the world if I remember wikipedia correctly. I wonder if any country built enough shortly after reach other / in parallel / same company building in multiple countries at the same time to see an effect of scaling (materials, knowledge, experience, navigating the legislation, ...).

Furthermore, energy being X% more expensive for the next hundred years might just be the reality we have to live with in order to reach net zero realistically. (Looks like this is happening due to gas prices right now anyway, so we might as well have gone nuclear... ten years ago it was obvious that we would want to stop burning gas some time soon, but not that solar panels would become so cheap so fast, so it would have made sense, and yet...) The alternative to spending a bit extra on your energy bill is spending way more on climate adaptation, from growing food to relocating people to building sea walls in many if not most countries.

South korea is by far the biggest producer of nuclear plants. Their prices have gone down slightly after building dozens of plants, but nuclear is still more expensive than solar for them. Until we get a legitimate fission innovation plus the political will for deregulation nuclear prices will remain sky high.

> [even then,] still more expensive than solar

Also more expensive than climate change adaptation?

I know it's a big and, truth be told, unanswerable question I'm asking. I just mean to say: can we really afford to pinch pennies here, comparing the cheapest forms of energy we have today (like solar) as a benchmark which it must beat before we consider a low-carbon low-landuse low-risk* base load to be a good addition to the grid?

So long as it's not prohibitively expensive, at least.

* near-negligible chance but a fairly large impact (not in death/cancer toll, at least not compared to gas/coal even if you scale it per kWh, but in evacuation and cleanup costs), at least when not considering that we might build better reactors than we did in the 60s (even if we probably would) (Fukushima and Chernobyl were designed before my parents were born and I'm not a teenager anymore). I can see how people find this not danger-free, even if most of it is misguided, especially when you're not near the biggest fault line of this planet

Uncouth way of putting it, but I think you hit the nail on the head. A massive increase in the available energy supply would allow us to do things we can barely dream of these days. To me, it almost feels like energy availability corresponds to how advanced the society is, and from that perspective it's weird to me that there's such a push for actually reducing our energy usage and output.

Nuclear power is among the most expensive forms of energy available to us. "Too cheap to meter" never materialized. A "FUCKTON" of nuclear plants will also take decades to build and produce zero power while under construction.

You know why? Because of fearmongering, redtape, and utter bullshit detractors every step of the way.

Nuclear power could be cheap and pervasive and safe and clean.

But noooooo. We have had decades of bullshit from people who barely got through 5th grade science making policies or voting in people making policies.

People piss themselves when you mention "nuclear" and other energy companies played it up.

That might or might not be the true cause for the high price of nuclear. But in any case the chances of us getting rid of the regulations in the next five years are essentially zero. So any hopes to have abundant, cheap nuclear power this decade, or even the next, are pipedreams.

> Want to keep the Air conditioning on while you're not even home? Yup, No one cares.

Switching off AC for 8 hours (1/3 of day) when you are not at home doesn't save even 10% of energy, you will just burn the "saved" energy trying to cool down the house when you will switch it on again. There was study published just last week about it.

https://arstechnica.com/science/2022/08/does-turning-the-air...

EDIT: once again downvoted for providing hard facts because some can't accept even quoted studies

> you will just burn the "saved" energy trying to cool down the house

Did you read the article you linked? It says:

> What we found was that even when the A/C temporarily spikes to recover from the higher indoor temperatures, the overall energy consumption in the setback cases is still less than when maintaining a constant temperature throughout the day.

Even if you ignore the whole thing (as I should have, I was validating their method because the conclusion you cited sounded wrong... but then it turns out the conclusion isn't what you claim) and just read the concluding two sentences of the post, you'd have read: "An eight-hour setback on weekdays provides savings regardless of the system type"

It's a convenient myth that not turning off the heating when you're not home saves energy because the heater would otherwise have to work extra hard when you come home / wake up and consume more energy. I've heard it told by people that usually have sensible opinions. I guess it's the inverse myth in the hot places of this world. It is indeed very nice to walk into a climate-controlled place, so I can see why people love to believe it.

It makes no sense. Think about it: in the scenario where you let the AC run all day long (or leave the heater on overnight), the temperature differential between inside and outside is larger. More heat enters/leaves the house when the differential is greater, so it makes sense to let this grow smaller when you're not there anyway and only increase the differential when you're (almost) coming home or coming out from under the blankets.

Did you read the sentence after the one you quoted? It then says

>On an annual scale with a conventional central A/C, this could result in energy savings of up to 11 percent.

That's basically what the poster above was claiming (though they seemed to be under-estimating the effect a little). Obviously turning the AC off will reduce the amount of heat leaving the house, but the point is the gains are not super large, even with an inefficient AC and a poorly insulated house. If you have an efficient AC and a well insulated house then the difference could be even smaller (it's even possible that the trend could reverse at some point, if the efficiency of the AC goes down when it is pumping more heat to cool down faster as opposed to consistent low-power heating: you can actually see this in the charts if you look at the mini-split system: it actually uses less energy to turn run the system all the time than to have it off for 4 hours a day, though 8 hours off time is still more efficient). Add in the effects discussed elsewhere in this thread where not all energy consumption is equal from the point of view of the grid and it may even make sense to do the opposite: run the A/C hard during the day while you're not home but green electricity is cheap so you can have it off when you get home and elecriticy demand spikes and solar power is falling off, flattening out the dreaded 'duck curve'.

I said "not even 10%", they say "up to 11%" (at best), so I wouldn't say I am underestimating the effect at all.

It's a nitpick mostly put in place to try to fend off a nit-picky reply of "Well OP said <10% and the article says <11% so OP is still wrong".

Heat pumps and condensing gas boilers both run more efficiently if run for longer periods at lower intensities.

If you have a poorly insulated house and an old non-condensing boiler it probably makes financial sense to only heat when you are there.

For modern homes, you want good insulation and a heat pump running constantly at high efficiency and low output.

There some minor quirks (time of use rates, weather prediction/conpendation) but thats the general gist.

You get various co-benefits from running the system at lower temp consistently, the high heat-cold cycles are bad for various physical things.

I'm having a hard time finding good information on this, or at least I was a few months ago when I was looking into whether I'm being stupid for thinking essentially what I said in the last paragraph. Do you have a link where I could read more about why it makes sense for heat pumps? I don't understand why the same logic shouldn't apply there.

These guys cover it, and despite the cheesy Youtube thumbnail, cover it with reasonable nuance:

https://www.heatgeek.com/should-your-heating-be-left-on-all-...

> heat loss is not the same as fuel consumption.

> That is to say, if a property lost 40kW/h of heat through its walls throughout a 24 hour period, that typically doesn't mean you have used 40kW/h of gas from your boiler or 40kW/h of electricity from your heat pump.

> If the boiler has consistently run at 85% efficiency you will use 47kW/h of gas. If you can get 93% efficiency from that same appliance you will only use 43kWh gas.

> And therein lies the problem. Many arguments for turning the heating off are talking about saving heat loss, not saving primary fuel usage. The difference between the two relies heavily on the first variable we need to ask ourselves, what is our heat source?

(That "kW/h" is a red flag for me. I'm not super knowledgeable about electricity myself, so if a blog can't even tell kWh from kWh/h from kW/h, I usually try to avoid it. Anyway, this is not a random source that I found but something being vouched for, so I'll trust it.)

This seems to be the core argument:

> most people have condensing boilers. These can run at lower temperatures which cause some of the fumes to condense into liquid water (hence the name). And this action extracts extra efficiency from the appliance.

> If you have a heat pump, the gains from running at lower temperatures are even higher here. Running at high temperatures of 50 to 55°C all the time year-round to maximise the responsiveness of the unit, and switching the heat pump on and off regularly will result in [~half the] efficiency.

I like this comparison:

> It's a bit like saying, I'm going to drive 100mph to the shops as I'll only be driving for 30 seconds. Actually, if you drive at 5 mph you will take 3 mins, it may ‘take longer’ but it will be much more efficient with fuel.

Because it also highlights the fallacy: this is wrong. At 5 mi/h, my car uses something like 30l/100km (rough estimate, maybe +/-10). At 40mi/h, it's around 3.3l/100km if I remember correctly (+/-0.3). But, yeah, at 100 mi/h you're obviously battling a lot of air resistance and slower would be more efficient... just not excessively slow.

The article would benefit from some actual numbers. It explains the general concept, but how many hours would you have to leave it off for, for it to be more efficient again? Is there a formula or curve to use with time on the X axis and... house volume or outside temperature on the Y or something, or are there too many variables to dumb it down to a line that works as general advice per heater type in typical climates? Surely for those that don't work from home, using reverse AC to blow some hot air, for 15 minutes in the bathroom and 30 minutes in the kitchen while you get ready in the morning, is more efficient than having base heating turned on during the 8 hours that you sleep + 2×45 minutes that you commute + 8 hours that you work?

But I understand the concept at least, thanks for the link!

The link at the bottom about why zonal heating doesn't make sense gets deep into the numbers and calculations.

I hadnt read the Ars Technica link before, but it makes the same argument, with graphs, a low efficiency device in a poorly insulated home left off for a 4 hour period makes sense, but in that situation you probably want to insulate and/or use a more efficient heat pump rather than do that.

Why would a heat pump run more efficiently when maintaining a temperature differential? From my rudimentary physics knowledge, a heat pump works best when the temperature difference between hot and cool side is lowest. So the first Joule pumped out of a warm house is the cheapest.

Yes I read and you can see clearly on charts switching of AC for 1/3 of time (8 hours) saves only ~10% energy. So yes, you will save negligible amount of energy by having switched off AC for non-negligible amount of time.

> It's a convenient myth that not turning off the heating when you're not home saves energy

Stop twisting my words, I didn't say anything like that, I just said thosae savings are negligible and irelevant.

Not just you who's saying that, but it's a thing that keeps being repeated. You didn't say it helped at all, while in reality it does. That's the thing people are going to remember.

Ask anyone if they want a 10% discount on their energy bill (while helping the environment / energy transition to boot) and see what they say. I don't think it's going to be "nah, not worth it".

I said "it doesn't save even 10% of energy", maybe work on your reading skills if that means for your it doesn't help at all.

Yeah and ask those people if they wanna come for this saving to hot home. This negligible at best 10% discount ain't for free, it cost you convenience which I value at more than some negligible saving.

Want a ton of cheap hydrogen for all your clean non-battery vehicles/rockets? You got it.

In the US what political party is the "Nuclear Party"? This is one of the major things I'm going to be looking for come voting season.

None. We have a "Fossil Fuels Party" and a "Renewables Party."

Yup, because nuclear power requires humongous government investment, so the party of small government is never going to go for it, while nuclear has a bad reputation both from a cost efficiency, lead time, and a safety point of view, so a progressive party is not likely to go for it when renewables are a much more attractive looking solution.

I thought you have a "fossil fuels are cool and manly" party and a "fossil fuels are important for corporate interests" party. But that's just my impression as an outsider.

I would have said "Renewables (but really mostly just fossil fuels) Party" but recent legislation makes it seem like the Democrats may be getting more serious on renewables.

Nuclear is a political loser. Making it affordable requires massive deregulation which will absolutely end up costing votes, and it'll only show benefits after a decade, so no politician will support it.