The time has finally come for geothermal energy

I've always been curious why a cost-effective widespread implementation of geothermal energy has never been considered a holy grail of energy production, at least not in the public debate. Much of the discussion is so focussed on nuclear fusion, which seems so much harder and less likely to be reliable.

It always has been. Our problem is switching over existing infrastructure without asinine complainers ruining the revolution. We can't even declare total victory with LED bulbs over incandescent. The war to have solar plants over more coal is falling back to coal thanks mostly to AI. Pushback on geothermal will arrive, I guarantee it.

at some point we will figure out that because we took some much energy out of earths core that it stops spinning and causes the magnetic field to collapse ;-)

Probably because not everywhere on earth has the same easy access that Iceland has. The article mentions this:

> There aren’t gates of Hell just anywhere. A kilometre below ground in Kamchatka is considerably hotter than a kilometre below ground in Kansas. There is also readily accessible geothermal energy in Kenya (where it provides almost fifty per cent of the country’s energy), New Zealand (about twenty per cent), and the Philippines (about fifteen per cent)—all volcanic areas along tectonic rifts. But in less Hadean landscapes the costs and uncertainties of drilling deep in search of sufficient heat have curtailed development.

I think it mainly depends on how easy it is to access that energy. I went to Tuscany last year and to my surprise there were geothermal plants everywhere. I have never heard about these plants beforehand, but here they are in Italy quietly powering the countryside and heating greenhouses to grow basil all year around.

> falling back to coal thanks mostly to AI

citation needed

Not really how that works. Also earths core is being heated from nuclear decay and tidal effects. It’s getting 10’s or TW worth of heat until the sun expands and eats the earth. https://en.wikipedia.org/wiki/Earth's_internal_heat_budget

Drilling is one of those things which used to be extremely expensive but has very gradually come down in price. Thanks, ironically, to the oil industry. It's unsexy because there's no "silver bullet" waiting in the wings.

It's also quite hard to find suitably hot rocks suitably close to the surface.

Focusing on fusion .. I think that's a legacy of 60s SF, when the fission revolution was still promising "energy too cheap to meter".

There have been numerous trials that had to be stopped because of the triggered earthquakes... Geothermal is not so easy.

People across the road from have geothermal, driven by a 1.5m-deep pond right near their house. Their heat never costs more than $100 a month in the winter.

I think they meant that as a joke.

Because unless you sit on top of a volcano, amount of renewable geothermal energy is minuscule. In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!). In other words, in most places geothermal plant acts more like a limited battery powered by hot rock, so unless drilling is extremely cheap, it does not make economic sense compared to other energy sources.

That's a different "geothermal" - the correct name is "ground source heat pump" or in your neighbor's case, a pond-source heat pump. Those exploit the temperature stability that occurs some small numbers or meters subsurface for heating in the winter and cooling in the summer.

"Geothermal energy" involves drilling down to hot rock to tap intense heat to run a turbine that produces electricity.

I think OP meant technology for drilling becoming cheaper rather than the near-surface availability of it.

Thanks for that wikipedia link, it's fascinating!

It's nuclear fission. It's always been nuclear fission (well, at least since the '50s) and it will continue to be until we commercialize fusion reactors. Everything else is nice to have but it's like NIH syndrome.

> The war to have solar plants over more coal is falling back to coal thanks mostly to AI.

Also, due to solar not panning out at scale.[1]

More seriously, coal is just cheaper and, with incentives being removed for green energy, it's the cheapest and fastest option to deploy. It's dead simple and well understood reliable power.

[1]https://apnews.com/article/california-solar-energy-ivanpah-b...

Plasma drilling is a recent development that looks promising for unlocking deeper wells for geothermal.

Geothermal is fission, and wind, solar, and batteries are fusion at a distance. In both cases, the failure scenarios are benign vs traditional fission generation. It's fine to keep striving for fusion humans control, but the problem (global electrification and transition to low carbon generation) is already solved with the tech we have today. It took the world 68 years to achieve the first 1TW of solar PV. The next 1TW took 2 years. Globally, ~760GW of solar PV is deployed per year (as of this comment), and will at some point hit ~1TW/year of deployment between now and 2030.

Geothermal is a great fit for dispatchable power to replace coal and fossil gas today (where able); batteries are almost cheaper than the cost to ship them, but geothermal would also help solve for seasonal deltas in demand vs supply ("diurnal storage").

https://reneweconomy.com.au/it-took-68-years-for-the-world-t...

https://ember-energy.org/data/2030-global-renewable-target-t...

I also love geothermal for district heating in latitudes that call for it; flooded legacy mines appear to be a potential solution for that use case.

Flooded UK coalmines could provide low-carbon cheap heat 'for generations' - https://news.ycombinator.com/item?id=45860049 - November 2025

There is an enormous push to build and power data centers in the DC / Northern Virginia region, and there's legislation in West Virginia right now requiring all coal-fired power plants to operate at at least 69% capacity at all times to support it.

> “West Virginia has numerous coal plants that have powered this country for decades. We need these plants to remain operational,” [WV Governor] Morrisey said. “… We will never turn our backs on our existing coal plants and we will work with the federal government to pursue new coal-fired generation.”

https://westvirginiawatch.com/2025/09/11/morrisey-shares-new...

https://wvpublic.org/story/energy-environment/data-center-bi...

https://www.wvlegislature.gov/Bill_Status/bills_text.cfm?bil...

> We can't even declare total victory with LED bulbs over incandescent.

The LED bulbs I have access to (whatever's in the aisles at Home Depot, Costco, etc.) fail much more frequently than the incandescent bulbs I used to buy, and produce an uglier light that is less warm even on the softest/warmest color settings.

My suspicion is that incandescents were at the "end" of their product lifecycle (high quality available for cheap) and LEDs are nearing the middle (medium quality available for cheap), and that I should buy more expensive LED bulbs, but I still think that there are valid "complaints" against the state of widespread LED lighting. I hope these complaints become invalid within a decade, but for now I still miss the experience of buildings lit by incandescent light.

The other thing with AI--the LED revolution was led on this idea that we all need to work as hard as we can to save energy, but now apparently with AI that's no longer the case, and while I understand that this is just due to which political cabals have control of the regulatory machinery at any given time, it's still frustrating.

There is a crazy amount of energy available everywhere but it is not in the interest of the very powerful very wealthy existing players. This isn't some grand CONSPIRACY. For example oil companies may construct energy investment portfolios that would quite sensibly acquire promising energy related research. They do a simple cost benefit analysis then chose to modestly further research it or shelve it. They turn it into valuable pieces of paper that accumulate value over time. What is there for them not to like about it?

I like how David Hamel put it: We live in this thin sliver on the surface of the planet where it is reasonably peaceful. This is the tranquility! It's a good thing! If you go up or down by a mere few miles there is so much energy it kills you.

The example you chose is of a mirror based Solar system, which yes, is an obsolete technology.

Direct solar continues to be installed at greater amounts every year and coal is economically uncompetitive with basic anything (which is why it is collapsing), and especially against natural gas.

Instead of drilling deep, there is also an intersting case for storing cheap solar energy as hat in piles of dirts in the summer to power turbines in the winter: https://austinvernon.site/blog/standardthermal.html

Maybe buy your bulbs somewhere else? I'm yet to replace any of the LED bulbs I've bought over the past 15 years and honestly can't even remember the last time a bulb failed.

> The LED bulbs I have access to (whatever's in the aisles at Home Depot, Costco, etc.) fail much more frequently than the incandescent bulbs I used to buy, and produce an uglier light that is less warm even on the softest/warmest color settings.

LED lamps work just fine, you just need to pay more attention when you’re buying them. Philips makes decent LED lamps.

Make sure you’re buying lamps with 90+ CRI, that will help with the quality of light. 2700K is a good color temp for indoor living room/dining room/bedroom lighting, 3500-4000K for kitchen/garage/task lighting.

You also need to buy special lamps if you put them in an enclosed fixture, look for ‘enclosed fixture’ rated lamps. Regular LED lamps will overheat in an enclosed fixture.

Why not is explained in David McKay's book Sustainable Energy - without the hot air

https://www.withouthotair.com/c16/page_96.shtml

The problems are that rock isn't a good conductor of heat, so once you've cooled a bit down, you have to wait for it to warm up. Warming only happens very slowly at the rate of < 50mW / m² which limits the amount of power you can get out.

Wild take. New coal is not cheaper. There have been no new coal plants built in the US since 2013.

That solar plant you linked is an obsolete experimental technology. Obsolete because regular PV became so much cheaper.

The only way new coal plants get built from today on is with massive lifetime subsidies, because they are uncompetitive. Ie, if they get built it’s for dumb politics not economics

Many others here have talked about the difficulties of geothermal, which doesn't really get to the heart of my question: why the lack of hype around breaking down those difficulties? I appreciate that you took the time to comment on why it isn't so sexy, the SF argument probably has a lot to do with it.

That sounds like they want to subsidize the coal industry. AI is just the excuse.

Failure scenario in modern fission reactors is also benign. Reactors are designed to lock down to prevent any leaks.

We deploy solar PV capacity, this doesn't mean we actually get that much power from the deployments. Nuclear fission provides reliable, baseload power, and doesn't require huge battery arrays to compensate for the sun setting or winds calming.

Ive been very pro nuclear my whole life, but a part of me is disheartened by the mega projects that commercial fission deployments have become (even if the reasons are bad) that’s a problem that nerfs traditional fission. If nuclear remains both political, extremely bureaucratic and requires public investment, it just won’t be the solution, and not because the tech or physics is bad, but the decision makers & investors can no longer organize large infrastructure projects effectively (except maybe China). This is not unique to nuclear.

Having smaller scale local power generation, whether it’s SMRs, solar, wind or geothermal, there’s a huge advantage in terms of economy, investment, and politics.

Was going to mention that point: http://www.seismo.ethz.ch/en/knowledge/geothermal-energy-ear...

The worst earthquake that was induced that way was 3.5, but given that one of the quakes happened in an area that had a catastrophic earthquake in the Middle Ages, some caution might be warranted: https://en.wikipedia.org/wiki/1356_Basel_earthquake

Enough renewables are deployed annually to replace the global nuclear fission fleet, year after year, even when accounting for capacity factor derating (to make a like for like comparison). The race is over, and renewables (with batteries) won. If you can find someone unsophisticated to invest in a fission reactor that takes billions of dollars and 10-15 years to build, more power to you. There will be no need for it by 2035-2040 when it prepares to send its first kwh to the grid.

(and to stay on topic for this thread, geothermal is a component of this when geothermal potential exists, cost is competitive, and dispatachability is a requirement to push out fossil generation in concert with renewables, hydro, legacy nuclear, battery storage discharge, and demand response)

https://www.google.com/search?q=baseload+is+a+myth

https://cleantechnica.com/2025/11/15/coal-killing-sodium-ion...

https://ember-energy.org/latest-insights/q3-global-power-rep...

https://ember-energy.org/latest-insights/solar-electricity-e...

https://ember-energy.org/latest-insights/solar-electricity-e...

https://world-nuclear.org/information-library/economic-aspec...

https://www.lazard.com/research-insights/levelized-cost-of-e...

https://ourworldindata.org/grapher/solar-pv-prices

https://ourworldindata.org/battery-price-decline

https://ourworldindata.org/data-insights/solar-panel-prices-...

https://news.ycombinator.com/item?id=44513185 (lfp battery storage cost citation in 2025)

That's a really good point, and it does take the wind out of the sails. Isn't it possible that eventually we could drill deeper?

> uglier light that is less warm

I figured out why this happens.

The light color they call "daytime" is around 5000K, so I expected it to look like being outside in the sun; but instead I got a cold blueish vibe. The problem? Not enough power! I got the equivalent of a moonlit room.

So I got this 180W LED lamp (that's actual 180W, not 180W equivalent) [1]. It's so bright I couldn't see for 5 minutes. I put two in my office on desk lamps. The room now looks like being outside, without the "ugly blue" tint, even though the product says it's 6000K. The days of my SAD suffering are over!

[1] https://www.amazon.com/dp/B0962X573M

Nuclear is great, but it does require wheelbarrows of cash, and we don’t have a solution for waste products.

You're exactly right and it raises a question for me. Why do energy generation topics bring people out of the woodworks who cite some very idiosycratic one-off and use it to make out-of-proportion declarations about the utility of a given technology? This is the second one I've seen suggesting solar is doomed when they mean mirrors.

On twitter I saw someone claim PV is useless for heat because non-PV solar water heating is just so much more efficient. Not even true (I think it's a approximately a wash, different advantages in different applications), but very strangely in the weeds on a specific topic. Much too narrow a factual context to substantiate general level claims about solar as an energy writ large.

I think for whatever reason the missing the forest for the trees trap is really potent in energy discussions.

Remains to be seen, it has serious trouble with water getting into the borehole.

> New coal is not cheaper.

I see yow it can read that way but it isn't what I said. Coal plants exist, either shuttered or running low loads due to financial incentives (not favoring them).

Studies show solar is cheaper but businesses continue to choose coal. I think the entity who's entire existence depends on them making the correct financial choice is a much better indicator of economic reality than a study made by people who have zero stake (at best) in the game.

I'm all for green energy but I also don't think people are stupid.

The world's total energy consumption (most of which is fossil fuels) is currently estimated at 620 exajoules, or 17TWh / year.

Assuming zero growth in energy consumption (hello AI), extracting even half of that seems like it would be consequential.

> In most places on Earth it's somewhere around 40 mW/m2 (i.e. accounting for conversion losses you need to capture heat from ~500 m2 to renewably power one LED light bulb!)

Ground-source heat pumps extract about 1000 times more power from ground loops, where does the difference come from?

Things are more expensive when we keep reinventing the wheel and trying to do new things instead of just reusing proven designs. Remember that solar power also used to cost wheelbarrows of cash back in the day. When you do something repeatedly, it becomes less expensive over time.

Nuclear is actually the leader in waste management. No other energy source has as complete a story. Eg what happens to solar panels when they EOL in 25 years? They go into landfills and leach toxic chemicals into the ground. These chemicals, like lead and cadmium are toxic forever. They have no 'half-life' in which their toxicity reduces.

Solar panels are recycled at almost 100% of total materials. Redwood Materials (founded by Tesla's former CTO) has already established a supply chain to ingest and recycle EV and stationary storage batteries at scale. The problem is that the hardware is lasting longer than expected, and meaningful recycling volume does not yet exist.

Conversely, ~95,000 metric tons of nuclear waste in the US does not have permanent storage or recycling solutions, as of this comment, and there is no plan for long term storage or recycling. Nuclear generation is experiencing a negative learning curve; we keep spending more the more we attempt to build it.

(solar PV panels have a 25-30 year service life, at which point they will still produce power at ~80-85% initial rating, batteries have a 15-20 year service life, with sodium ion chemistries estimated to have up to 50 year service life assuming once daily cycling)

https://www.epa.gov/hw/solar-panel-recycling

https://www.energy.gov/eere/solar/articles/beyond-recycling-...

https://e360.yale.edu/features/solar-energy-panels-recycling

https://www.cnbc.com/2025/11/09/nuclear-power-energy-radioac...

https://www.gao.gov/nuclear-waste-disposal

https://decarbonization.visualcapitalist.com/visualizing-all...

(nuclear power accounts for about 10% of electricity generation globally, as of this comment)

> If you can find someone unsophisticated to invest in a fission reactor that takes billions of dollars and 10-15 years to build

Unsophisticated investors like the Chinese government? 'Nearly every Chinese nuclear project that has entered service since 2010 has achieved construction in 7 years or less.'

https://thebreakthrough.org/issues/energy/chinas-impressive-...

The problem is how do you remove the incumbents. Oil lobby is pretty strong. Imagine what would happen to car lobby once we have teleportation.

Nuclear has broad bipartisan support, and the Trump administration is heavily into it, so I wouldn't count it out just yet. If the various Green parties of the Western world ever come into power though, we are cooked.

Drill baby drill!

Seriously this would be such a dream!

Turns out that the best battery is literally 10 feet away* - and you don't even need to charge it!

*if you want to make steam its a few thousand, but for heating and cooling its literally just 10 feet!

Actually, since posting this I've vaguely remembered a previous discussion on here about differences between LED bulbs sold in the US and those sold in UK/EU so maybe that explains it.

They dabble in nuclear, but it is not their focus. China can do what the developed world cannot because they are a command economy with less expensive labor, which will only last for a bit longer due to their structural demographics. Unless the developed world no longer has labor regulations, developed world wages, and capital based allocation systems, my statement stands with regards to investment. If capital and labor does not matter, certainly, anything is possible (Paraoh demanding pyramids, for example).

Your citation comes from an organization with pro nuclear bias.

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

Can China Break Nuclear Power’s Cost Curse—and What Can the US Learn? - https://rooseveltinstitute.org/blog/can-china-break-nuclear-... - September 17th, 2025

China built more solar power in the last 8 months than all the nuclear power built in the entire world in the entire history of human civilisation. And even if you adjust for utilisation rate to compare against nuclear utilisation China built more solar power generated per hour than all the nuclear power currently in operation generate in an hour - and did so in 12-18 months - https://bsky.app/profile/climatenews.bsky.social/post/3lggqu... - January 23, 2025

China is installing the wind and solar equivalent of five large nuclear power stations per week - https://www.abc.net.au/news/science/2024-07-16/chinas-renewa... - July 15th, 2024

Nuclear Continues To Lag Far Behind Renewables In China Deployments - https://cleantechnica.com/2024/01/12/nuclear-continues-to-la... - January 12th, 2024

Nuclear Energy & Free Market Capitalism Aren’t Compatible - https://cleantechnica.com/2023/11/06/nuclear-energy-free-mar... - November 6th, 2023

https://x.com/MoreBirths/status/1910780131318374524 | https://archive.today/iu9jx (China demographics citation)

Baseload generation is useless in 2025. It's in the name; it's called "base load", not "base generation".

Base generation was a cost optimization. Planners noticed that load never dropped below a specific level, and that cheapest power was from a plant designed to run 100% of the time rather than one designed to turn on and off frequently. So they could reduce cost by building a mix of base and peaker generation plants.

In 2025, that's no longer the case. The cheapest power is solar & wind, which produces power intermittently. And the next cheapest power is dispatchable.

To take advantage of this cheap intermittent power, we need a way to provide power when the sun isn't shining and the wind isn't blowing. Which is provided by storage and/or peaker plants.

That's what we need. If added non-dispatchable power to that mix than we're displacing cheap solar/wind with more expensive mix, and still not eliminating the need for further storage/peaker plants.

If non-dispatchable power is significantly cheaper than storage and/or peaker power than it's useful in a modern grid. That's not the case in 2025. The next cheapest power is natural gas, and it's dispatchable. If you restrict to clean options, storage & geographical diversity is cheaper than other options. Batteries for short term storage and pumped hydro for long term storage.

The Berlin one also had some promising news today: https://www.adlershof.de/en/news/successful-tests-on-undergr...

We have to see if and when any of them goes into production, but the technology seems very interesting

To be fair, that promise of fission made sense from a purely scientific and mathematical perspective, before running into the practical realities of how its externalities interact with real-world politics. Fission is expensive because in practice it turns out we care quite a lot about proper waste management, non-proliferation, and meltdown prevention.

In a world where anyone could just YOLO any reactor into production with minimal red tape, consequences be damned, fission energy would actually be extremely cheap. Hence the optimism around fusion. The promise of fusion is an actualization of last century's idealistic conception of fission. It can be a silver bullet for all intents and purposes, at least once it's established with a mature supply chain.

Harder absolutely but "less likely to be reliable"?

If economically viable fusion was "cracked" what would the nature of it's unreliability even be?

10 TW * 1 year = 8,760 TWh / year. The current rate of energy production is ~42TW and slowly dropping over billions of years, so even after efficiency losses gathering 1% of what’s produced is several times current energy consumption.

It could be but the US and EU have so far been unable to build commercial fission reactors without going 2x+ over budget in time and money. China is having success but even they are not projected to have nuclear account for more than single digit percentages of their generation.

Maybe SMR's, thorium, 4th gen, etc will work out, but maybe not.

If France–a country known for its strong labour laws and unions–could transition to nuclear in the '70s, any Western country can do it.

Even if the Western world lags behind due to labour regulations, the cost still pays off in the long run due to overall less complex infrastructure and stable, AC baseload power. You are thinking only about the cost of building. What about the cost of maintaining all that infrastructure? Huge solar and wind farms spread out over vast areas, essentially destroying the local ecology? NPPs have a relatively tiny footprint.

Every cited source has a bias. You think 'Clean Technica' is unbiased? Come on.

[CITATION NEEDED] They do not. If you take the mean, median, and mode of the failure lifetime for LED bulbs sold at these stores and compare them to the failure times of incandescent bulbs, I also guarantee you are empirically wrong here.

all the machinery used to obtain and maintain an economically viable fusion reaction. Having worked with particle accelerators and synchrotron rings, I'll tell you that stuff breaks down all the time.

Iceland's hot water was a culture shock to me in 2 ways:

1. The host at our apartment encouraged us to leave the windows cracked and the heat on for good air circulation.

2. The hot water (at the taps) has a sulfer smell, because it's (also) piped geothermal water. My host explained they also had a water heater upstairs in their home because they preferred "heated cold water" over "hot water", which is a funny distinction to those of us who do not have the latter.

Power flow is in general very low - ca 50-60 mW/sq.m

> Solar panels are recycled at almost 100% of total materials.

That's very clever wording. If someone glances at this sentence they might interpret it to mean that almost all solar panels are recycled. But your own citation tells a different story: https://e360.yale.edu/features/solar-energy-panels-recycling

> Today, roughly 90 percent of panels in the U.S. that have lost their efficiency due to age, or that are defective, end up in landfills because that option costs a fraction of recycling them.

Let's compare to spent nuclear fuel, which we know for sure does not end up in landfills. I am talking about today, not some hypothetical utopian future. Today, NPP spent fuel is safely sequestered while solar panels are dumped into landfills.

> nuclear waste in the US does not have permanent storage or recycling solutions

It does, it's just not built yet because it doesn't make sense to do it now. In a few decades, maybe a century we will have commercialized fusion reactors. Once we do, we switch to fusion completely and build the deep geological repositories or whatever other solution makes sense then. Or we can even recycle the spent fuel–the only thing stopping us from doing that now is misguided US politics (as usual).

> we keep spending more the more we attempt to build it.

It's capex. We are investing in nuclear technology. If you have a proven design and build the reactors at scale, the costs will flatten or decline, which is obvious to anyone who knows about economies of scale.

> If France–a country known for its strong labour laws and unions–could transition to nuclear in the '70s, any Western country can do it.

France had to nationalize EDF because they could not afford the costs associated with their nuclear fleet. The 70s are 50 years in the past, and are not what the future will look like.

This is also why Spain plans to retire its remaining nuclear generators, and go all in on renewables.

EDF fleet upkeep will cost over 100 billion euros by 2035, court of auditors says - https://www.reuters.com/business/energy/edf-fleet-upkeep-wil... - November 17th, 2025

French utility EDF lifts cost estimate for new reactors to 67 billion euros - Les Echos - https://www.reuters.com/business/energy/french-utility-edf-l... - March 4th, 2024

Explainer-Why a French plan to take full control of EDF is no cure-all - https://www.euronews.com/next/2022/07/07/edf-nationalistion - July 7th, 2022

Spain’s Nuclear Shutdown Set to Test Renewables Success Story - https://www.bloomberg.com/news/articles/2025-04-11/spain-s-n... | https://archive.today/4fB7K - April 11th, 2025 (“Spain is a postcard, a glimpse into the future where you’re not going to need baseload generators from 8am to 5pm” with solar and wind providing all of the grid’s needs during that time, said Kesavarthiniy Savarimuthu, a European power markets analyst with BloombergNEF. Still, she said, there is a reasonable chance this goal may take longer than expected and “extending the life of the nuclear fleet can prove as an insurance for these delays.”) (My note: As of this comment, Spain has 7.12GW of nuclear generation capacity per ree.es, and assuming ~1GW/month deployment rate seen in Germany, could replace this capacity with solar and batteries in ~28-36 months; per Electricity Maps, only 17.25% of Spain's electrical generation over the last twelve months has been sourced from this nuclear)

Tangentially, Europe has enough wind potential to power the world, for scale.

The options in the '70s were much different from those of today. And for France specifically what they have underground (lots of uranium, no oil, no gas & no coal) strongly suggested exactly one way forward.

Modern geothermal is dispatchable. It's a really good compliment to wind and solar https://climateinstitute.ca/safe-bets-wild-cards/advanced-ge...

The US Navy consistently builds reactors on-time and in-budget

Mine fail all the time. Cheap Amazon Basics, expensive Phillips.

Do they fail more than incandescents? idk maybe not, but they fail much more often than their advertising would suggest.

But is it usefully dispatchable? Nuclear can be made dispatchable but it's not usefully dispatchable because the costs are fairly similar whether the plant is on or off.

Like nuclear, I believe geothermal has high capital cost and low running costs, suggesting that it isn't usefully dispatchable.

But that's too simplistic. A big limitation of geothermal is that rock has poor thermal conductivity. So once you remove heat it takes a while for it to warm up again. If you're running it 100% then you need a large area to compensate. OTOH, if you're running it at a lower duty cycle you likely need less area.

So if you know the duty cycle in advance, then you can likely significantly reduce costs. Yay!

But that also means that you likely can't run a plant built for low duty cycles continuously for 2 weeks during a dankelflaute. It's likely great for smoothing out daily cycles, but not as good for smoothing out annual cycles. That means it's competing against batteries, which are also great for smoothing out daily cycles, and are very inexpensive.

> a holy grail of energy production

Since you're comparing it to nuclear, I'm assuming you mean electricity production here, not energy production?

It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%).

I suspect people confuse these two because in a residential context electricity plays a huge part of our energy usage, but as a whole it's a smaller part of total energy usage than most people imagine.

But any serious discussion of renewable energy should be careful not to make this very significant error.

The Lawrence Livermore National Laboratory publishes a great diagram of US energy use: https://flowcharts.llnl.gov/sites/flowcharts/files/2024-12/e...

I fully understand that waste management of fission reactors is a Very Big Deal. But I still stand behind the argument that opposing nuclear power in the 70s and onward is possibly the biggest own goal the environmental movement has ever achieved.

At worst, nuclear waste contaminates a discrete section of the Earth. Climate change affects literally everywhere. The correct answer would have been to aggressively roll out fission power 40-50 years ago and then pursue renewables. You can argue that other solutions would make fission power obsolete, but we would have been in a much better spot if it'd at least been a stepping stone off fossil fuels. Instead, we have 40-50 years of shrieking and FUD from environmentalists over an issue that can be kept under control with proper regulation. The US Navy has operated reactors for over 60 years without incident, proving it can be done with proper oversight.

TL;DR nuclear has issues, but I'd take it over coal every day and twice on Sundays, at least until something better can scale.

Couldn't you frac the rock like they do with oil and gas drilling or have a branching borehole?

I believe this is off by 5 or 6 orders of magnitude.

Looks like it's more like 200,000Twh / Yr

https://ourworldindata.org/energy-production-consumption

In 2025 the power consumption of my state (NSW, Australia) on any given day will be greater then 5 GW. https://www.aemo.com.au/energy-systems/electricity/national-...

This "there is no base load" idea is a ridiculous myth trivially disproven: every grid on the planet has continuous demands on it and they're quite significant (5 GW is about 50% the day time peaks).

It doesn't matter what the cost is, because later this evening or tomorrow morning I can guarantee you the same thing: my state will need at least 5GW of power to literally keep the lights on.

Well, heat pumps are awesome, but ground-source is overkill for many places where the air temps don't fall too low (and it's a lot harder to drill holes behind your house).

> Why do energy generation topics bring people out of the woodworks who cite some very idiosycratic one-off and use it to make out-of-proportion declarations about the utility of a given technology?

They either have only read propaganda pieces from fossil fuel producers or are trying to create some of those.

I would expect the number of people that honestly don't know anything but propaganda to be way higher than the number of people creating propaganda. But there's probably a selection bias due to HN being a somewhat large site with some influence on SEO and AI training.

I agree. I think the correct environmentalist position at that time wouldn't have been to oppose nuclear, but to advocate for improvements, streamlined approvals of improved designs, and public investment or incentives.

I wasn't really commenting on the merits of 20th century environmentalist movements, more raising the general point that fission power has inherent costs which weren't reflected by narrow 1950s analyses of how much energy was extractable from U-235. Operation of a fission plant requires much more capex and opex than it would if we didn't care about cleanliness (waste management), security (fissile material theft prevention), or safety (meltdown prevention).

Fusion power is more complex to invent and practically depends on modern technologies that didn't exist 50 years ago, but once the first demonstration plants are operational, marginal costs to deploy and operate more should be much lower and ultimately become very low at scale.

wouldn't it be "natural geothermal" if the pond is a naturally occurring hot spring?

What does "Rejected Energy" mean in that graph?

Great chart, by the way.

The right answer is 'yes to all the above'. Yes, we need solar. Yes, we need wind. Yes, we need batteries and, yes, we should be looking at geothermal. Solar has shown us, again, how artificially holding back a technology for decades has massive costs. Investing a few billion into geothermal right now is cheap and can only lead to a more durable energy infrastructure in the future. There are all sorts of benefits to a rich ecosystem of power generation. Solar and batteries may be amazing but global supply chains can be disrupted. Similarly, having multiple solutions means that niche use cases have more options and a larger likelihood of finding an acceptable solution. So, yes to all of the above. We are big enough to try them all.

That Newberry Crater one is really close to where I live and... it'd be so amazing if it came to fruition. It sounds almost 'too good to be true'.

> Drilling is one of those things which used to be extremely expensive but has very gradually come down in price. Thanks, ironically, to the oil industry. It's unsexy because there's no "silver bullet" waiting in the wings. It's also quite hard to find suitably hot rocks suitably close to the surface.

That's basically it. Most geothermal plants today are in locations where there are hot rocks, maybe geysers, close to the surface. "Deep geothermal" gets talked about, because temperatures high enough for steam are available almost everywhere if you can drill 3,000 meters down. There are very few wells in the world that deep, not counting horizontal drilling runs.

The economics are iffy. You drill one of the most expensive wells ever drilled, and you get a medium-pressure steam line. Average output is tens of megawatts.[1]

[1] https://pangea.stanford.edu/ERE/db/GeoConf/papers/SGW/2020/A...

That’s a lot of words to admit that geothermal has its place.

Baseload is traditionally about generation, not consumption. And baseload generation only makes sense when it is the cheapest option.

When solar and wind produce at near-zero marginal cost, running inflexible baseload beside them just forces cheaper generation to switch off, driving up system costs.

What the grid needs is dispatchable capacity - batteries, hydro, gas peakers (if we must) and demand shifting - that can plug the gaps when cheaper forms of generation cannot.

A lot of housing politics from 'old school' environmentalist groups are a pretty big own goal as well.

Denser urban living is pretty energy efficient, and forcing lengthy commutes on people because of NIMBYism is a huge waste.

Rejected energy means energy that is lost as waste heat without performing any work first. For example, a coal fired power plant may generate 3 megajoules of thermal energy from coal combustion but only deliver 1 megajoule of it as electricity. The other 2 megajoules are lost as useless waste heat.

The 1 megajoule of useful electricity is also ultimately dissipated as low grade heat, but it can do work first (like generating light, or pumping water uphill).

You misunderstand the point though. Sure there is always 5GW of demand - but we don't need generation that always supply 5GW cheap since wind/solar is much cheaper for base load. What we need is non-base load generation that can jump in at a moment's notice when needed because wind/solar isn't enough. Previously we would use those peak plants from when there was 6GW of demand (or whatever), but now between those peak plants coming down in price and wind/solar being so cheap we don't want that 5GW from plants that cannot adjust to load anymore - we are getting the can't adjust to load from wind/solar.

Only about 30% of the energy in gasoline is converted to useful work in a gasoline car (the 'make metal box go forward' part). The remaining 70% is Rejected Energy (the steam you see going out the tail pipe in winter).

Which (not sure if you did this intentionally or accidentally) brings up an interesting point on the parent comment and the LLNL sankey:

> It's always worth remembering that electricity only accounts for ~20% of global energy consumption (in the US it's closer to 33%).

That "global energy consumption" figure includes a lot of Rejected Energy going out tailpipes and smoke stacks turning burnables into electricity. A secret bonus of wind and solar is if you produce electricity without burning things, you actually decrease the energy demand! If you're not losing 70% of your energy consumption to the Rejected category, you suddenly need a lot less total energy.

A number of sources. Often the air above - ground source relies on the ground being the average temperature of the year round air once you get deep. They also tend to run in heating mode half the year, and cooling mode the other half.

I live in a part of the world that is far below freezing for a significant portion of the year. Thus a large portion of my annual energy usage goes into not freezing to death.

When I drive my daughter to school when it’s -40 fucking degrees, a lot of the energy I use goes into heating my vehicle, swearing, moving and swearing. But this energy also leaks through my windshield, through my exhaust system and through my engine. This energy (heat) doesn’t provide any benefit to anyone and just leaks out into the atmosphere (which we’ve already established is trying to kill me).

That’s rejected energy. Or when it’s below -40, rejected motherfucking energy. :)

That wasn't the conclusion, though. The conclusion was that dispatchable geothermal is competing against daily cycling batteries, a competition it's likely to lose on cost.

> Solar and batteries may be amazing but global supply chains can be disrupted.

Solar and batteries aren't consumables, so they're not particularly vulnerable to supply chain disruption. If we lose our supply of batteries, we'll have ~10 years or so to find an alternate supply. We won't be able to do new installations during the disruption, but existing installations don't stop working.

Unlike a fossil plant when the supply of fuel is disrupted.

One thing which is needed too is spinning load, the grid depends on having enough inertia to maintain the frequency. Flywheels I assume would do that.

People want houses. Planners can either yell and stomp their feet about this or adapt to circumstances. It's like electric cars. People want cars. Better they have the ability to have an electric SUV or pickup, because if you try to force them into little tiny econoboxes or lecture them about how they should really be using mass transit, they're just going to flip you the bird and walk away.

Similarly, better to have people be able to have reasonably energy-efficient houses than demanding they all live in apartments.

It wouldn't work very well for cooling then

I believe this is true for the LED technology compared to the incandescent technology as a whole, but I'm simply turning over bulbs at a far higher rate than I did in the incandescent days. Often the LED bulbs are failing within a year under normal usage patterns. It's possible that using modern LEDs in old fixtures is causing some kind of issue.

People want a place to call home. Those come in many shapes and sizes. Denser living does not mean a smaller living space. By building 'up', you can provide both.

The only ones demanding anything are those who show up to try and stop apartments.

Inverters and batteries (or any other DC source) are also very good at doing this.

The economics change when you’re in oil country. My beautiful little province has oil wells drilled between 250 and 2900 metres. Due to corporate ‘issues’ many of these wells are orphaned and remediation becomes a provincial problem. With deep holes and provincially owned electricity and gas companies, geothermal makes more economic sense; it’s robbing a benefit from a big cost centre.

I went to high school with two guys who are working on geothermal as a means to remediate orphan wells. I’m biased in their favour, but the numbers make a lot of sense.

Not grid following inverters, or "any DC source", as we saw in Spain in Summer

I was wondering how feasible it would be to reuse abandoned oil pumps for geothermal energy. A closed loop system [1] would probably be the most appropriate, with energy generation by spinning of a turbine by steam that gets recycled. I don't have the expertise and was wondering if someone can share a bit of knowledge with the rest of us.

[1]: https://en.wikipedia.org/wiki/Closed-loop_geothermal

We’re trying that in Germany while we’re still heavily dependent on coal while our electricity prices are twice as much compared to France.

I’m sorry, but wind and solar may be cheap, but they don’t provide cheap electricity 24/7.

It sounds great in theory but doesn’t work in practice.

Just compare Germany to France.

Or just build out nuclear like France and pay just 20 Cents per kWh.

https://particulier.edf.fr/content/dam/2-Actifs/Documents/Of...

Look at Electricity Maps and realize that France is the only large industrial country where electricity generation is permanently carbon-free and cheap.

https://particulier.edf.fr/content/dam/2-Actifs/Documents/Of...

Nothing to do with the blackout in Spain - https://www.reuters.com/business/energy/what-caused-iberian-... - voltage surge and various thermal power generators failing to provide the voltage correction services they were being paid for

But yes, grid following alone does not provided the required stability - synthetic inertia etc needed

When heating is dirt (heh) cheap, it doesn't cost much to do things like put big hot tubs and heated pools outdoors, like they do in Reykjaviks swim halls. It's really nice.

»Enough renewables are deployed annually to replace the global nuclear fission fleet, year after year, even when accounting for capacity factor derating (to make a like for like comparison).«

Wind and solar do not replace conventional power plants and never will.

Heck, Germany tried that on the small island of Pellworm and failed and yet some people think this will work out for the whole country.

It does not work.

At home I use 15,000kWh of oil for heating each year (about 10kWh per litre, 1500 litres), and 8,000kWh of electricity (we use a lot more than the average household). For driving that's another 5000kWh a year if at 4 miles per kWh.

So even in a residential context, electricity is only about 1/4 of the demand. Across the whole country it's less than 300TWh out of 1500TWh, under 20%.

That excludes "imported energy" though, as in goods which used energy to make but were then imported.

Yes, but unfortunately that is because it is coasting on decades old labor and capital investment that will not be made again. It is not permanent, as it will cost tens of billions of euros to continue to operate those generators reaching the end of their service life.

which is why dispatchable power is required - not coal?

»Your citation comes from an organization with pro nuclear bias.«

Go and throw all your money into renewables stocks and ETFs if you’re so convinced.

I bet you’re not doing that because you realize that the industry isn’t doing well and it’s nuclear power nowadays where all the money goes.

Wind and solar existed in the 70s as well.

Plus, Germany invested 500 billion Euros in its energy transition and is STILL heavily dependent on coal.

This is being done and it's called synthetic inertia. Just with capacitors and batteries instead of spinning motors.

Personally, I've invested ~500k EUR in a Portuguese Golden Visa fund invested in renewables (IRR is ~7-13%). Macro speaking, renewables investments keep hitting new records. I am convinced, and if you are not, I would strongly suggest consuming more data, because you appear to have a potential blind spot in your mental model on this topic.

https://about.bnef.com/insights/clean-energy/global-renewabl...

https://www.bloomberg.com/opinion/articles/2025-10-28/white-...

»It could be but the US and EU have so far been unable to build commercial fission reactors without going 2x+ over budget in time and money.«

The EU also forgot how to build airports and train stations on budget and on time.

Should we stop building airports and train stations?

As for nuclear power plants: Germany and France built most of their reactors on budget and on time.

Caterpillar provides some really neat small scale flywheel UPS - used in places like hospitals where it would be very bad to lose power. They last long enough for the diesel gennies to start up.

Yes, if you don't install grid stabilization inverters, they don't supply grid stabilization.

Yes please from the UK, where it’s 27 euro cents per kWh currently.

Norway, Iceland and British Columbia are other examples and are more carbon-free than France is. The latter isn't a country and the former don't count as "large industrial"?

P.S. this is a response to the original title, which has since changed making my comment look off-topic.

A IC car’s heating system normally taps into the engine’s cooling system, so that heat is mostly free. In a pinch you can actually turn the heater on full to help cool the radiator.

Ignore the clickbait headline here: Australia’s Solar Boom Is Breaking the Grid - Or Is It?

It's a sub 15 minute actual grid engineering for lay public explainer video (I know, I'm not a video fan either)

A better duller title might be: How Australia's Grid is being adapted to Solar Boom

  00:00 Introduction
  01:23 The Problem with Too Much Solar
  03:29 Batteries Change the Economics
  05:40 What the Grid Actually Needs
  07:04 A Cautionary Tale – The 2025 Iberian Blackout
  08:21 Australia’s Secret Weapon – Experience with Weak Grids
  10:08 The Genius Technical Fix – Grid-Forming Inverters
  12:25 The Perfect Partner - Batteries
  12:58 From Mechanical to Software-Defined Stability
  13:42 Conclusion – Fixing the Grid Before It Breaks

https://www.youtube.com/watch?v=qavFbOpt4jA

They've already made a move about that. https://www.imdb.com/title/tt0298814/

Purely as an aside, I had the pleasure of visiting Iceland in August and it was great. Truly beautiful, rugged land.

Another way they've utilised geothermal energy is with large, sophisticated greenhouses which allow growing of many produce they would otherwise import. I only had the opportunity for a brief visit but a lot of it looked hydroponic with really interesting monitoring and control technology. (Plus the biggest bees this Antipodean has ever seen! These suckers were so big they didn't buzz, they rang the doorbell.)

Sorry the time had not come for geothermal. It will always be an expensive niche market. Will there be more? Sure but its ever going to fly globally.

There’s something to be said for a standardised design with replaceable parts.

Allowing people to live in apartments is not demanding that they do.

Reversing the downzoning of the 70s - 00s is about allowing construction in cities again.

The two nukes that recently came on line in the US were so over budget and timeline that all customers now pay a “surcharge” on their bill to pay for it.

Western counties building nukes is so expensive it makes the cost of electricity go up.

Suitable locations for pumped hydro are very limited, it is a comparably rare resource.

A lot of mountainous places are dry, and a lot of wet places are flat.

Of the remaining places, some are so unique that they cannot be destroyed by industrial construction (National Parks etc.)

For example, the main ridge of Krkonoše (Riesengebirge) on the Polish-Czech border has a lot of wind and rain and deep valleys, but it is the only place south of Scandinavia with a Scandinavia-like tundra and many endemites surviving from the last Ice Age. Any attempt to construct pumped hydro there would result in a national uproar on both sides of the border.

"People want houses."

(Source needed. This probably depends on a lot of variables in play.)

Plenty of people in dense urban areas are happy with living in an apartment and, where I live, buying a condo in the city is at least as frequent as buying a house 20 km away from it for the same price.

Living in suburbia has its downsides - long commute, very limited entertainment and cultural possibilities, very limited choice in schools. Not everyone loves cutting the lawn etc. either, I surely don't. If any of your family members has any disease that could flare up, ambulance response time tends to grow worse with the growing distance.

Of course, a lot depends on factors such as "is the transport authority willing to make public transport actually safe and nice". That requires keeping raving drugged lunatics out of it, plus paying enough money for it. AFAIK in the US, Republicans have an ideological problem with the "paying money for it" part and the Democrats have an ideological problem with the "suppressing antisocial behavior in it" part.

People want houses, but absolutely hate other people having houses.

Back then, it affected everyone in two ways, which were the things Greenpeace campaigned against: nuclear weapons, especially overland testing, and dumping waste at sea.

Chernobyl took out Welsh farming for years, and in a few places decades, because it spread a thin layer of bioaccumulative poison over the whole of Europe.

It would be nice if before each box where rejected energy is an output, the inputs were split by rejected and non-rejected inputs.

But that illustrates the point. Most investors don’t want to put money towards something that may be put on indefinite hold depending on political winds. These projects are often much longer than presidential terms.

Yup - CRI is most important. Indoor house plants also like high CRI lights much more as well!

Its so easy that you can’t name me a single city of more than 10000 people that runs entirely off renewables.

Neither of these have anything to do with running a well-regulated nuclear power program. Chernobyl happened because of the apathy and incompetence endemic to any Marxist-Leninist system, not because a modern democratic state is incapable of regulating the nuclear power industry.

Know what else spreads a thin layer of poison over the whole of the world? Coal power.

That's the current load when the pricing structure actively encourages people to use power at night, because that was when it was cheapest to produce in the last century.

What does it look like if you actively encourage people to use power when it is cheapest to produce now?

I guess we'll find out when 3 hours of free electricity at noon becomes a standard offer next year.

State subsided construction and maintenance doesn’t pass straight through to consumer prices.

Also, France can’t build new nuclear for cheap/fast anymore either. They have a program for new reactors, even if they go ahead the first one won’t come online till 2038 by the earliest. We can’t wait that long.

This is such a tired trope. The differences between the two countries present day energy situation doesn’t tell you anything about how the world should proceed tomorrow.

Unless you have a time machine that you can use to get every country to build state subsided nuclear 50 years ago.

> I believe geothermal has high capital cost and low running costs

Higher capital costs, but not nuclear high capital costs.

> That means it's competing against batteries, which are also great for smoothing out daily cycles, and are very inexpensive.

It likely would supplement batteries rather than compete against them. A battery buffer would allow a geothermal plant to slowly rise to load and fall as that load goes away.

A very large battery can store 200MWh worth of energy. The largest geothermal plant produces 1.5GW. (A lot of the large plants look like they are in the range of 100->200MW). Presumably those plants can run for more than a few hours which ultimately decreases the amount of batteries needed to smooth out the demand curve.

Until recently, the geographical locations where geothermal is feasible and economic was very limited. Ironically it is tech from fracking/shale gas that is starting to open up a far wider range of possible sites at lower cost.

Are your LED lamps failing in enclosed fixtures? You need to buy special lamps for enclosed fixtures, regular LED lamps will heat up too much for enclosed fixtures.

Look for ‘enclosed fixture rated’ LED lamps for enclosed fixtures.

> Wind and solar existed in the 70s as well.

Not really. Solar has gone down in price almost 500X since 1975.

https://ourworldindata.org/grapher/solar-pv-prices

Wind has gone down significantly too.

https://docs.nrel.gov/docs/fy12osti/54526.pdf

Meanwhile, the graph for nuclear waste disposal is going rapidly in the opposite direction.

https://www.ans.org/news/article-6587/us-spent-fuel-liabilit...

http://large.stanford.edu/courses/2024/ph240/kendall1/

A nuclear plant about 50 miles from my house was closed 15 years ago. The spent fuel rods will be stored there indefinitely until a federal facility is built.

They’re at ~60% total power from renewables in 2025, and increasing every quarter. I’d say they’re doing pretty well! The coal is unfortunate, but was due to the Ukraine war and gas situation.

50+ years ago, not relevant.

Suitable locations for on river pumped hydro are limited.

But off river? The possibilities are vast.

Not even France can replicate their nuclear construction of decades ago.

The reactor breaking and taking a very long time to repair because the repairs would have to be done remotely, with robots. The structure becomes too activated for people to go inside, even after the reactor is shut off.

The reactor breaks because it's a large device operated at high stresses (power/area, neutron loading). There are many components and joints that can fail.

BTW, this means fusion will be expensive, because getting all those components to be reliable right off the bat becomes expensive. No tiny cracks in the welds means expensive quality control.

One of the benefits of over-provisioning solar is that fun "wasteful" things that use a lot of energy become practical and non-harmful.

Norway and British Columbia are 99% renewable energy and they have many cities larger than that.

France is a western country with its own economic and labour troubles. The enormous expense of building nukes in the US is entirely its own making and much more complicated than just "western" inefficiency.

> pumped hydro for long term storage.

You are using long-term in an extremely vague way.

Pumped hydro is not a solution for seasonal storage or yearly storage. Seasonal variation can be a problem in higher latitudes.

For example we have a serious problem in New Zealand where our existing "green" hydro lakes are sometimes low and our economy is affected: creating national power crises during dry years. We use coal-burning Huntley and peakers to somewhat cover occasional low hydro generation.

Unfortunately our existing generators also have regulatory capture, and they prevent generating competition (e.g. new solar farms) through rather dirty tactics (according to the insider I spoke with).

Apparently much of our hydro generation is equivalent to “run-of-river” which requires the river to flow. Although the lakes themselves are large, they don't have enough capacity to cover a dry year.

NZ had planned a pumped hydro, but it was expensive: planned cost of 16 billion compared against total NZ export income of ~100 billion. https://www.rnz.co.nz/news/national/503816/govt-confirms-it-... So completely uneconomic risk (plus other problems like NIMBY).

Do you live out in Siberia or something? Seems like a rough environment for most tech.

Sounds like a very unique experience :)

Pumped hydro just requires a lake at the bottom of a slope. Unlike hydro generation, it doesn't require flow. Here's almost a million locations suitable for pumped hydro: https://re100.eng.anu.edu.au/global/

Two farm dams at a minimum, one at either end of a slope.

You can serve a small town of 500 or so people (plus tourists) with a mini systems for ~ $8 million (AU)

https://news.ycombinator.com/item?id=45332157

nobody ever seems to recognize the benefits of Modularising your grid as well.

Ukraine is an excellent example of why centralizing your grid energy source is a bad plan... but not just for war situations. If you have an agile, adaptable modular grid you can recover for any form of disaster (natural or man made) very quickly and cheaply.

I really feel this is an under valued aspect of electrification and greening of the power sources we use.

I've worked on mine sites that use this as well.

Hyper administrative state-capitalist economies all have the same problem with infrastructure. The US has an image of being more capitalist and efficient, which is true to a degree, but once you get a large-scale project that hits all fed->state->municipal politics it's not much different than France. It's just minor variations of who the mandatory 'stakeholders' are ...who demands a cut and who delays/blocks progress.

As soon as some project is being pitched by politicians as "creating thousands of local jobs" it's either DOA or will be many years late and over budget.

I hadn't realized that the IDDP had hit magma! That's very exciting! Obviously I'm very out of date, since that was in 02008.

However, I'm skeptical that geothermal energy can be economically competitive with solar without major innovations in heat engines, no matter how abundant the energy is and how easily you can get that energy to the surface.

https://www.eia.gov/analysis/studies/powerplants/capitalcost... outlines the estimated costs (five years ago) of a 650MW peak ultra-supercritical coal power plant without carbon capture; the total capital cost estimate comes out to US$2.4 billion, which is US$3.70 per peak watt. Of that, I think the only line item that wouldn't be the same in a 650MW peak ultra-supercritical geothermal plant is "Mechanical – Boiler Plant", which is US$905 million, leaving US$1.5 billion, US$2.30 per peak watt. (I'm not even sure you could eliminate even all of that US$905 million in a geothermal plant; some of it might be plumbing you'd also need to pass heat from your downhole heat exchange fluid with the ultra-pure deionized water you use to drive the delicate steam turbine. But let's suppose you could.) Of that US$1.5 billion, US$155.2 million is "Mechanical – Turbine Plant", so the turbine alone costs 24¢/Wp.

But SEIA last year published https://www.seia.org/research-resources/solar-market-insight.... They have a set of cost breakdowns for “turnkey installed price” for power plants, coming in at 98¢ per watt for “utility-scale fixed-tilt”, slightly higher than the previous year and almost half due to about 40¢ for the PV module itself. Residential is at 325¢, with about 20¢ for the PV module. That's even in the US, where the EIA report's estimates were sited, despite the US's prohibitive import tariffs on solar panels from China, which makes most of the world's solar panels.

Mainstream PV modules are now 12.3¢ per peak watt https://www.solarserver.de/photovoltaik-preis-pv-modul-preis... (except in the US), which would drop SEIA's cost estimates from 98¢/Wp to 70¢/Wp, even in the absence of any other cost optimizations in solar farm design.

Now, utility-scale fixed-tilt solar farms typically have a capacity factor of around 20%, depending on latitude, because the sun is below the horizon half the time and somewhat slanted and/or clouded most of the rest of the time, so 70¢/Wp is really about US$3.50 per watt, not counting the batteries. But geothermal typically only has a capacity factor of around 74% in the US https://en.wikipedia.org/wiki/Capacity_factor#Capacity_facto... so US$2.30/Wp is really US$3.10 per watt.

That leaves you 30¢/Wp (74% × ($3.50 - $3.10)) for geothermal exploration and drilling. And if you can reduce the 82% of the solar 70¢/Wp represented by the non-PV-module costs by a little bit, or if you're equatorial enough that your PV capacity factor is 23% or above, that's going to zero or negative. I think the average PV capacity factor in California is something like 29%, though that isn't fixed-tilt and therefore has slightly higher costs.

Also note that the PVXchange page I linked above lists "low-cost" solar panels as having fallen to €0.050/Wp this month, a new historic low, which is 5.9¢/Wp. That's a 50% price decline from two years ago.

Fundamentally I think it's just going to be very hard for 24¢/Wp steam engines to compete against 5.9¢/Wp solar panels. The steam engines have the additional disadvantage that, to get the price even that low, you need enormous degrees of centralization—on the order of a few thousand power plants for the whole population of the US. This requires long-distance electrical transmission lines as well as local distribution lines, which are both substantial costs of their own as well as wasting a double-digit percentage of the energy. Local electrical generation eliminates those costs; you can charge your cellphone or your angle-grinder battery directly from a 5.9¢/Wp solar panel with no more electronics than a couple of protection diodes, not requiring the rest of the 70¢/Wp in the utility-scale solar plant.

This cost analysis is completely indifferent to where the heat to boil the water comes from, so it applies equally well to nuclear power, except for Helion.

The exceptions would be in places where geothermal energy is available and solar energy is either unavailable or very marginal: the surface of Venus, the ocean floor, Antarctica, Svalbard, etc.

Does anyone have a trustworthy estimate of the costs of drilling? Even drilling into cold rocks (for oil) would be a good start, even if hot rocks are more expensive to drill into. The article says that Fervo has raised US$800 million in capital and drilled three appraisal and demonstration wells with it so far, which gives us a ballpark of US$200 million per well. This does not offer much hope that drilling costs will be a minor fraction of the costs of a geothermal plant.

The article unfortunately doesn't enter into this analysis at all.

I am somewhat skeptical of this figure:

> Geothermal energy production in the U.S. at that time [i.e., 02005] was around three or four thousand megawatts.

https://en.wikipedia.org/wiki/Electricity_sector_of_the_Unit... says that geothermal energy production in the US in 02022 was 16.09 billion kWh per year, which is 1825 megawatts. Does that mean that geothermal energy production fell by about half between 02005 and 02022? More likely Rivka Galchen got confused.

It's unfortunate that the article also confuses ground-source heat pumps (thermal energy storage) with geothermal energy sources. It's a common confusion, and it makes conversations about geothermal energy unnecessarily difficult.

Long term storage is definitely the weak point of moving to 100% carbon free electricity. Unfortunately geothermal does not cover this need. If we want to cover a dankelflaute with geothermal, we basically need enough geothermal to cover ~100% of our power needs. Pumped hydro is the best answer we have at the moment, even if it isn't a great answer.

What will likely happen is that people will decide that "99% is good enough", and use fossil generators to cover dankelflautes,

My favorite memory is following a map to a small isolated hot spring off of some random gravel road in the middle of nowhere. It consisted of a hot-tub-sized pool and a shower.

Whoever was there before had left the shower running. We were the only people there, and hadn't seen anyone pass us on the (dead end) road, so it must have been on for quite a while.

Only when I went to for my pre-soak shower did I realize that it didn't actually have any kind of user-accessible way to turn it off.

Solar + wind is being installed at about 100x the rate of fission because it's so expensive. And the differential is only increasing.

installs: https://www.pv-magazine.com/2025/01/13/the-fastest-energy-ch...

costs: https://www.reddit.com/r/energy/comments/11q58pe/price_trend...

You may need small amounts of rare earth elements. Those are definitely a supply chain nightmare.

This feels a bit like talking in hindsight.

With fossil power plants, the bigger plants were more efficient. This lead to centralization. We now find ourselves in a situation where you can end up with a lot of small/local generation.

What happened in Ukraine can probably happen in almost every developed country today as this was all built/planned in a different time.

yeah I'm not saying that they messed up, I'm saying that we dont appear to be taking note from the situation. Doing better based one the world as it is now and how history has played out.

You might want to look up flammanville. They built a new reactor there and that also took 20 years or so and was way over budget.

We've built a lot of nuclear in the last century and then largely stopped. A lot of the know how is gone which is what we're paying for now.

Also, in France, all those reactors were largely the same leading to economies of scale when building them. Everything we build today is essentially a one of so you don't get to spread that cost over multiple.

I don't have knowledge, but my understanding based on a conversation I had on the topic with a friend of mine is that the "let's use hydraulic fracturing to make geothermal energy feasible in North America" idea involves drilling very far down. Oil is on [average][1] about a mile down, while [one of Fervo's wells][2] is three times deeper.

[1]: https://www.eia.gov/dnav/ng/ng_enr_welldep_s1_a.htm

[2]: https://fervoenergy.com/fervo-energy-pushes-envelope/

Which is honestly fine, we would be in such an amazing place if we got to 99%

Nuclear produces very dangerous substances. The long term cost to guard us from them for a million years and the risk that something gets out of control are extemly high.

I brought up the mirror plant because the molten salt crucible is an example of an attempt to make solar work after hours. It wasn't viable.

Solar+storage is not a solved problem. The storage problem gets continually hand waived away in the conversations about how cheap solar is.

As I said in a sibling comment, I don't think the people running energy companies are stupid. If solar really was cheaper as a baseline power supply, what it needs to be to replace fossil fuels, they'd be doing it.

> but existing installations don't stop working.

They will, albeit slowly.

> Although the lakes themselves are large, they don't have enough capacity to cover a dry year.

It was shocking to me to drive by many of the California lakes/reservoirs that were overfull in the spring of 2019 only to hear that they were basically running dry two years later, and realize that as substantial a water storage system as they are, they're not multi-year scale against the required water supply.

Weakly defined. What does "run entirely off renewables" mean?

We know that in North America, for example, significant energy use comes from transportation and heating requirements, and that at this time, very little transportation is powered by renewables, and not a whole lot of heat either (though both are growing).

On the other hand, the entire current residential electrical demand of the city of Santa Fe (about 82k people) can be met with a single relatively small PV+BESS plant (and might just be if it manages to get built).

Yes, that's what this article is about.

While it's true that a geothermal plant is a limited battery powered by hot rock, that doesn't mean it doesn't make economic sense compared to other energy sources.

Ground-source heat pumps are irrelevant to geothermal energy sources, and it's unfortunate that the article mentioned them. Ground-source heat pumps are just storing heat from the air during the summer and retrieving it during the winter.

It also explains why this is no longer a problem.

"when it’s -40 fucking degrees" Celsius, or Fahrenheit? Oh yeah, it's the same either way :).

> Wind and solar existed in the 70s as well.

This is basically nonsense to the extent that it is becoming difficult to extend the presumption of good faith to you. In the 70s solar panels cost US$25+ per peak watt, in 02021-adjusted dollars: https://en.wikipedia.org/wiki/Solar_energy#/media/File:Solar...

Now they cost 5.9¢ per peak watt: https://www.solarserver.de/photovoltaik-preis-pv-modul-preis...

Installing a gigawatt of solar power generation capacity for US$25 billion is in no way comparable to installing a gigawatt of solar power generation capacity for US$59 million.

Wind power has experienced a similar but less extreme cost decline.

Solar panels do not become useless in 25 years and need to be discarded, do not leach toxic chemicals, and do not contain cadmium. They do contain small amounts of lead, but leaching metallic lead out of landfills is very difficult and probably does not ever happen unintentionally.

The US and Russian Navies deciding to remain mostly petroleum-fueled is one of the strongest arguments against nuclear becoming very cheap: surely they would do it if it wasn't ruinously expensive, because it eliminates the national security risk of a petroleum blockade and simplifies at-sea logistics immediately.

In many cases you can break one of the resistors off the LED bulb's printed-circuit board and run them at two-thirds of the power so they last forever. In other cases the surgery required is a little more involved than just snapping a surface-mount resistor off with pliers.

None of this will change the CRI.

I think houseplants will like horticultural LEDs much more than high-CRI lights.

There are scifi stories that have that kind of premise. Here's one, about electric power: "Damned if you don't" by Randall Garrett (https://www.gutenberg.org/cache/epub/24064/pg24064-images.ht...). I think there was also one about teleportation, although I can't remember where I read it.

> my state will need at least 5GW of power to literally keep the lights on.

I think this abstraction is missing the elasticity of demand that can by unlocked by end-to-end dynamic pricing. Probably if the production was cut in half for some day, and hourly price hiked up until demand matches production, customers would still choose to keep most of the lighting while postponing some more energy intensive loads.

> If solar really was cheaper as a baseline power supply, what it needs to be to replace fossil fuels, they'd be doing it.

So, you haven't looked at what energy companies are doing for the last 3 years...

I had to do that when my radiator sprang a leak on the freeway and the engine heat kept creeping up. Unfortunately it was late summer and not at all pleasant.

I managed to get to a gas station with some stop leak in stock... If they didn't, I was ready to crack an egg in it.

Not OP, but upper Midwest US and Canada experience this every year, though where I'm at usually only hits -40 if you include the wind chill.

From what I saw: In Spain, inverters are not allowed to provide voltage control, and what we saw in Spain, was a voltage spike that caused generators to drop offline, which then caused frequency issues.

Yes but a very small amount and it is nothing we don't know how to manage.

> the risk that something gets out of control are extemly high

Except this is false, you are just spreading misinformation. I suggest you confront your current knowledge to different sources and listen to the arguments of the proponents of nuclear energy before you make up your mind. Don't just repeat what you have heard.

One underappreciated challenge in geothermal is simply the distribution of usable rock formations — low-prevalence resources. Better drilling reduces the rarity penalty by making more sites viable. Similar structure to many screening problems: improve detection and you can shift what counts as "reachable."

Don't presume too much about the US Navy's fleet decisions. Using that same logic you could presume that smaller, aged and poorly maintained fleets are advantageous for naval supremacy since that appears to be the choice of the US Navy for a couple generations now.

Or you could presume that the complete inability to build a merchant marine fleet was also a strategic advantage!

68 years ago we already had fission plants. the engineering side of energy production has been solved since then, it's all political now

that seems fine

I don't know much about militaries or nuclear reactors, but I know that reactors are used in some submarines and in some aircraft carriers -- situations where you want a vessel to to remain at sea for long periods of time without refueling, and weight is not a primary concern.

That's pretty niche, though. Think about trucks, tanks, aircraft, generators for outposts, etc. It might be cool if you could safely package a zillion nuclear reactors for those use cases, Terminator style, but I'd guess that reactors are a better fit for centralized, permanent power generation.

Canada as a whole is roughly 70% hydroelectric.

Any substance with a half-life of a million years is giving off very, very tiny levels of radiation.

What you should worry about is half-lives of under a few years.

I saw these in the basement of a data center about 11-12 years ago. Most steampunk thing I've seen in real life.

I would guess dankelflaute is mostly irrelevant in New Zealand because our hydro lakes (assuming rivers are flowing) can smooth out generation shortfalls shorter than say a month (kinda equivalent to pumped hydro or batteries). A 3 day dankelflaute as given in the Wikipedia example would likely not matter in New Zealand. Plus our weather is variable, and generation is spread out.

  New Zealand's hydro storage is less than a sixth of the country's total yearly electricity use. Hydro generation typically accounts for over 50% of our annual electricity generation, making us reliant on river flows. The maximum storage (full lakes) is around 5 TWh.

The lakes can't smooth out over long periods.

About 20% of New Zealand electricity comes from geothermal. I would guess political and environmental issues would dominate costs for increasing geothermal generation (plus I would assume we've taken all the low hanging fruit).

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

> Unfortunately geothermal does not cover this need.

Artificial geothermal could though.

https://www.orcasciences.com/articles/standard-thermal

The size is orders of magnitude smaller than the depth of natural geothermal wells, and the temperature much higher. Even so, they are aiming for heat loss of < 1%/month, entirely adequate for seasonal energy storage.

> Geothermal is fission

Geothermal is not nuclear fission. The heat comes from a combination of primordial heat (from the gravitational energy turned to heat as the Earth formed) and radioactive decay (which is some combination of alpha and beta decays; spontaneous fission is extremely rare.)

See report and first comment: https://news.ycombinator.com/item?id=44358668

It looked to me that regulators wanted to make solar the scapegoat for political reasons.

The report indicates to me that different operators were using a random monkey theory to make changes until the grid stabilised (they clearly didn't have a handle on the root cause of the instabilities). The regulator screwed up: they are supposed to engineer the network so it can be stable (even in the face of political pressure).

It's not just the US Navy. It's also the Russian Navy, the French Navy, the Chinese navy of the PLA, the British Navy, the Indian Navy. If nuclear power were cheaper than oil, or anything other than much more expensive, at least one of those would have gone all-nuclear.

People want a lot of things, many of them conflicting. I'd love a huge house on a large lot in a walkable area and it to be cheap, and also close to nature. Letting markets work is a good way of resolving people's revealed preferences. Some will prefer a condo in a walkable area, others a large lot outside a less expensive city, others will pay through the nose to have a single detached unit in a high cost of living area.

To me the most important fact to keep in mind about geothermal is that the energy flow across the crust is ~0.1W/m^2. Compare that to the sun which has >100W/m^2 even at high latitudes. Of course this does not mean geothermal is useless (in particular heat pumps, if you count those, are great), but it goes a long way to explaining why geothermal isn't seeing the same explosion as solar.

Not for solar, and not for most forms of Li-ion batteries.

Sure. Building out renewables while still keeping their coal/methane plants running. Then again, with the abundance of rooftop solar where it's economical, there's really no need for utility level solar. Wind is good still but also inconsistent.

With the way power demand is growing, new fossil plants aren't being built really because renewables can pick up a lot of the new demand but solar is at the point in some places where utilities don't want your excess power.

Renewables are great in the places they fit but they don't fit everywhere.

Note though that the sulfur smell from hot water in Iceland is only a thing in certain areas in Reykjavik, and perhaps some locations around the island.

This is due to the hot water in those regions literally being pumped out of the ground and into homes, and on a completely separate plumbing system. Majority of other areas use heat exchangers with pristine cold water, thus no smell nor taste is transferred.

So if you are staying in any other municipality in the capitol, you can use the hot water in cooking directly without boiling cold water. It's the same.

It probably also depends on where you are and how deep you need to drill. It seems to be working out for Munich in Germany, there are a couple of city districts (including mine) that are heated by geothermal, and they invested in this since the early 2000s. Can't really find an english page for the whole project though: https://www.swm.de/unternehmen/geothermie

Here's a bigger one at ASDEX (a fusion experiment):

https://www.ipp.mpg.de/4244138/generatoren

The way I understand it from people working in the field, is that the issue isn't really that lakes/rivers are running dry, but more that most hydropower is produced on the South Island while most consumption is on the North Island and the connection is woefully inadequate (typical NZ problem, never invest in infrastructure just keep bandaiding it). That said installing wind and solar (both of which are plentiful) would do a lot towards alleviating the problems, but there are the issues of the existing generators lobbying and the political climate, where the conservative party still has a significant number of politicians who think climate change isn't real.

True DC grids avoid this stability issue by not having a phase and allowing power flow to pretty much just self-balance through voltage gradients and clipping of connections/devices to whatever current they can handle.

With enough voltage range that wouldn't even need the tricky loops of voltage regulation common in incandescent-targeted legacy AC grids.

The problem with that argument is that nowhere did environmentalists in the 70s or 80s prevent nuclear power plants from being build. Nuclear has received much more subsidies than solar or wind ever did (even if we ignore the indirect military->civil subsidies) and it still never became economical. Back in the 70s and 80s coal was much cheaper, and now solar and wind are so much cheaper it doesn't make any sense to invest in nuclear. The nuclear power plants that were build, got built largely for political reasons (energy independence, and military), and the reason why not more got build was not those pesky environmentalists, but that it was expensive.

Agreed. I myself have always wanted a hobby smelting bauxite.

The French are wholly unable to build new nuclear power.

Flamanville 3 is 7x over budget and 12 years late on a 5 year construction program. The EPR2 program is in absolute shambles.

Currently they can’t even agree on how to fund the absolutely insanely bonkers subsidies.

Now targeting investment decision in H2 2026. And the French government just fell and was reformed because they are underwater in debt and have a spending problem which they can’t agree on how to fix.

A massive handout to the dead end nuclear industry sounds like the perfect solution!

The French were also practicing negative learning by doing.

https://www.sciencedirect.com/science/article/abs/pii/S03014...

Can confirm, I live in Georgia.

The real stickler is that just from pure lucky timing, data centers will likely be the direct beneficiaries of the third reactor coming online at the Vogle plant here in Georgia. So taxpayers foot and will foot the bill, and meanwhile our governor and mayor are tripping over themselves giving tax breaks to data centers.

While I agree about the coal thing:

Democracy just as lazy and apathetic is whatever the USSR counts as; the point of capitalism (which is different to democracy) redirect the laziness into something more productive — this works to an extent, but depends on competition which is greatly reduced in the case of nuclear reactors.

That it's a different axis than democracy-communism is also why the not-at-all-democratic military reactors around the world seem to be doing fine.

A very large battery storage site, like the top 10 currently running has an order of magnitude more energy storage than you suggest.

The largest under construction for go live in 2027 has another order of magnitude, 19000MWh and will deliver up to 1000MW.

Things are changing fast as battery prices drop and experience accumulates.

To my knowledge Siemens is currently making a lot of money by adding spinning inertia to the grid because that is easier than getting the response time/power out of electronics.

Is that correct only 1MW of power but 19,000MWh of storage? That would take over two years to drain it.

Powering an extended, worst-case-scenario month-long dunkelflaute entirely with gas rather than a realistic mix of options would only take 5% of Germany's current gas usage (coincidentally roughly equivalent to Germany's domestic gas production).

It's wild how much attention that gets compared to the 50% being used to heat buildings.

That is a problem for which we already have great solutions. We have German made heat pumps, that could be German fitted and run off German generated electricity, or worst case EU electricity imports.

Solve 10% of that problem and you have freed up enough gas and money to cancel out an apocalyptic scale dunkelflaute or three every year.

Well spotted, I've corrected to 1000MW (or 1GW).

The UEA are aiming for a longer than usual runtime, but only 19 hours, not 2 years.

"At present, atomic power presents an exceptionally costly and inconvenient means of obtaining energy which can be extracted much more economically from conventional fuels.… This is expensive power, not cheap power as the public has been led to believe." — C. G. Suits, Director of Research, General Electric, who was operating the Hanford reactors, 1951.

Safe, clean, too cheap to meter?

Some things never change.

The connection is not the issue.

  The issue is that we have insufficient extra generating capacity during a dry year. At the moment we don't have enough [gas] to fully use all our existing thermal plant in a dry year. There are no projects in the generation pipeline that would provide backup energy to cover dry years.

- https://www.mbie.govt.nz/dmsdocument/31240-factsheet-challen...

A lot more solar would help, but the government owned generators are knobbling private investment through dirty tactics (the details are not public - I got this from a planned utility scale solar farm that is being cock-blocked). Fundamentally the issue is that the generators make more money by preventing extra generating capacity coming online.

Don't blame "the conservative party": Labour were also completely useless when they were in power (admittedly National still isn't helping). Politicians rabbit on about infrastructure investment e.g. the link I gave that mentions the pumped hydro scheme backed by Labour and cancelled by National because it was uneconomic. Both parties wastefully "invest" in infrastructure, and both make stupid decisions to score political points rather than solve problems sensibly. It's nonsense to blame one party. Both parties are preventing utility scale solar installations (indirectly). And the minor parties are not helping either. The greens in particular are not a party to accept any compromise, so even they won't back solar.

Climate change isn't the cause here - your bias is showing.

Even Australian politicians and their regulator have managed to sort it out. New Zealand is just fucking it up.

Agreed. I like the smell of fluorides in the morning.

In what world are you living that you not have heard about nuclear accidents? Here is a reading list for you:

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

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

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

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

With regard to nuclear waste. Here is an example, how it can went quickly out of control:

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

does it matter much when in the end pricing is decided by merit-order system [1]? i.e. when you are dependent on other sources or neighbouring markets with very different composition.

not to say it is remains costlier than conventional sources, albeit not accounting for externalities.

[1] https://en.wikipedia.org/wiki/Merit_order

I’m relatively sure that at least in Germany the environmental movement had a lot of influence preventing the aggressive pursuit of nuclear power. Your point about subsidies still stands of course, but economics of power generation notoriously ignore the costs of climate change.

If it can be used to heat houses in winter it’s not irrelevant.

Pellworm is something like 95% renewable without storage. That really doesn’t sound like failure to me.

Yes I have and you clearly know nothing about those incidents else you wouldn't give a laundry list of wikipedia article you haven't even read.

I am not sure what your point exactly is

The C.G suits were right as long as the digging operation is not too costly (the more shallow and concentrated the better)

Fossil fuels are nothing short of a miracle because they are so energy dense, but it's a slow poison and has high addictive power.

As long as we didn't (want to) know about negative externalities (chief among them CO2 and CH4) whose cost was borne by humanity, it was ok. Dirty but everyone seemed to think it was worth it.

The advantages of nuclear is not that it would be too cheap to meter (even though that becomes true with time because most of the price is upfront investment).

- It is that you can get energy independence even if you don't have uranium because it is so energy dense that you can just stockpile it. For example France could run its plants for 2 years with its current stockpile of uranium, and it only recycles around 10% of its fuel. Compare that with its oil needs, the oil stockpile would only last 3 months, probably less.

- It is CO2 free

Bonus: Nuclear industry is required to take of its waste products (which are only waste products insofar are we are too lazy/cheap to recycle them, else they are just more fuel)

Insulation, adobe construction, and vigorous exercise can all "heat houses in winter" in the same way as ground-source heat pumps, but none of them can be meaningfully compared with hydroelectric or nuclear power except in a specific situation. How much insulation is enough to charge your cellphone or run a load of laundry? The question is nonsense.

The heating and driving could theoretically be electrified, though it might or might not make economic sense.

That could possibly be true, if fission is cheaper than solar, wind, and batteries.

The renewables are so cheap and quick to provision it's hard to see how fission can compete.

I dunno. Even China, which has built a lot of nuclear, is building way more renewables. Do you think they have it wrong somehow?

The figures I have seen seem to show that newly installed solar and wind is cheaper than running existing coal plants almost everywhere.

What businesses are choosing coal?

Maybe this is a stupid question, but is there any downside to harvesting heat from the planet? Would we slow convections by cooling it and then cause some weird ass problem?

I am afraid you will be the first to migrate after the energy crisis escalates. Next will be millions that live even a little below 0 (Celsius).

I am not in that field, just a curious citizen, but Siemens seems to offer synthetic inertia gear too: https://www.siemens-energy.com/global/en/home/products-servi...

And that location probably wasn't on the ANU map, meaning there were are far more than 1 million suitable locations.

I once rode in a friend's car in a similar situation. Very much not pleasant. His problem was a thermostat problem, so he hadn't lost all cooling but enough we used the same workaround. Running the heat in the summer time resulted in a couple of very sweaty dudes.

"They" are doing it! Remarkably, more than half of new energy generation deployed in the United States this year has been from solar. It's arguably the most shovel-ready form of energy infrastructure that exists right now.

Your framework is bizarre in the extreme. Despite the fact that no one thinks of mirror plants as having anything to do with the future of PV generation, you treat the future of all solar as if it hinges on that consideration. Meanwhile, back in reality, solar power could realistically occupy up to 30% of the grid's energy generation capacity without intermittency becoming a deal breaker. Combine that with the fact that the grid itself is going to continue to grow, and so 30% of whatever that future amount of total generation capacity is going to be a rather extraordinarily high number, solar is going to be an exceptionally important part of the energy generation picture in the future even if we never made an inch of progress on solving the intermittency problem. For that matter, it seems infinitely more rational to think that what's actually going to happen is some degree of experimenting with energy storage, more sophisticated demand management, and perhaps partner technologies that ease the stress of base load and peaking responsibilities. But instead of that, you're doing this completely out of left field U-turn towards solar mirrors.

So again, it's bizarre in the extreme to take that picture, which is about billions of dollars of grid infrastructure and multiple Terawatts of energy, and swap that out for a hypothetical relating to mirror plants, which is never going to happen in which no one is seriously entertaining, and to treat that question like it's decisive about the fate of solar power in the future.

This is what I mean about people coming out of the woodwork and treating big picture energy questions like they hinge on these bizarre idiosyncratic hypotheticals that have nothing to do with anything.

> while still keeping their coal/methane plants running

Methane, yes. The coal plants are being slowly shut down, as they are too expensive to run even after they were paid for.

You also seem to ignore the huge amount of utility-level PV farms and generation-side storage built recently. You are technically correct in that renewables don't fit everywhere, but that's again a common propaganda phrase because they fit the places where almost everybody lives, and long distance transmission already solves the problem for most people outside of that area.

'The most common reason that solar panels would be determined to be hazardous waste would be by meeting the characteristic of toxicity. Heavy metals like lead and cadmium may be leachable at such concentrations that waste panels would fail the toxicity characteristic leaching procedure (TCLP)'

https://www.epa.gov/hw/end-life-solar-panels-regulations-and...

'Today, roughly 90 percent of panels in the U.S. that have lost their efficiency due to age, or that are defective, end up in landfills because that option costs a fraction of recycling them.'

https://e360.yale.edu/features/solar-energy-panels-recycling

And for good measure: 'Recycling Lead for U.S. Car Batteries is Poisoning People'

https://www.nytimes.com/interactive/2025/11/18/world/africa/...

>while still keeping their coal/methane plants running

At lower capacity because their generation is being actively offset by renewables.

No, it makes sense because it's cheaper. At least, it is if we ignore the negative externalities and the future costs of maintenance of the infrastructure. Time will tell.

Yes, all of that is correct as far as it goes, and isn't in contradiction with what I said. You'll notice that the EPA page you linked https://www.epa.gov/hw/end-life-solar-panels-regulations-and... is mostly about an effort to reclassify solar panels as non-hazardous waste, which is specifically because of what I said. See for example https://www.sciencedirect.com/science/article/pii/S030147972... "About 8% of traditional PV samples exceed the 5 mg/L limit for Pb in TCLP tests. No modern PV samples exceed the 5 mg/L limit for Pb in TCLP tests."

But TCLP is already an extremely rigorous test, far worse than nearly all actual landfills, intentionally. It uses acetic acid, one of the very few acids that forms a soluble salt of lead, and none of the anions present in normal soils that normally immobilize lead, such as carbonate, phosphate, sulfate (!), and chloride.

And air pollution from pyrometallurgical recycling of the kilogram quantities of lead from car batteries is totally irrelevant to the safe containment of the milligram quantities of lead from (probably hydrometallurgical) recycling of solar panels. I am really struggling to imagine how your understanding of the issue could be so shallow that you thought it might be relevant.

Scrap lead is like US$1/kg. Nobody is going to recycle solar panels for that.

Exactly. It's also just bizarre to attempt to make the whole conversation about special one-off cases where some regions already have so much solar power that they won't benefit from adding more when such cases are not representative of the global picture, which is that there's abundant need going forward and abundant capability to build it out going forward.

So why focus on the unrepresentative cases, unless the intent is to be misleading? There'd better be a very good insight at the end of this road that's worth price of "accidentally" of invoking unrepresentative examples, and it better be something a hell of a lot more substantive than going "gosh renewables, gee, I don't know. Denmark sure has a lot of renewables already, don't forget about that! " It's the "You Forgot Poland" of energy debates.

Which will increase demand

Driving can push up the low points (charge cars overnight), but heating would put a lot of demand in winter months, meaning a day time cold day in January with no wind will require a lot of dispatchable electricity, at night time in September with a gale blowing wind will be providing almost all the demand.

Nuclear doesn't really help as it's more expensive than the wind when it's windy and demand is low, and its impossible to build enough to cover the peak January demand unless you spread the fixed cost over the entire year, which means getting rid of every other form of electric production, and you'd still end up paying more per kWh than you would with other forms of storage.

Nuclear can't survive in a free market. It can't scale up to provide for areas of high demand, low supply, and it can't scale down to be affordable when there's high supply and low demand.

You need them for solar inverters, but you also need them for the turbines like those used to generate power with geothermal/wind/hydro/nuclear/etc.

There are lots of houses getting the majority of their heat from ground source heat pumps. Not so many that are heated with vigorous exercise.

Ground-source heat pumps (with a few exceptions and borderline cases like those mentioned in the article) are not sources of heat, so you can only "get heat from" them in the short term; as with a battery or an interest-free checking account, though you may be able to temporarily run a debit balance, in the long run you can only get out what you put in.

This is a fundamental difference from energy sources.

Energy storage is an important complement to energy sources, especially renewables, and can substitute for energy sources to a limited extent, but confusing them is a fatal error.

Erbium perhaps for some power semiconductors, but in very small amounts.

What's the use in turbines? Most generators associated with turbines don't use permanent magnets.

Hmm, that doesn't sound right. Many homes don't use these heat pumps for cooling in the summer because getting convectors and plumbing installed is just as expensive as getting a separate AC, and then you have some redundancy in the system too.

I'm sure that battery effect is a factor but it must be a relatively minor one.

The Aircraft Reactor Experiment https://en.wikipedia.org/wiki/Aircraft_Reactor_Experiment, yielding 2.5 megawatts, was about two meters tall and one meter in diameter; the fuel was 15kg of U-235, but I think the reactor as a whole may have weighed several hundred kg. (It couldn't have been more than about 40 tonnes, just because no material would be dense enough, but I think it was much lighter than that.

Oh, here it is: https://media.githubusercontent.com/media/openmsr/msr-archiv... page 24/139 budgets 48400 "pounds" for "reactor and reactor shield", which is 22 tonnes, about 110kW/tonne.

The smallest nuclear submarine was NR-1, which had a total displacement of 400 "tons": https://en.wikipedia.org/wiki/American_submarine_NR-1 so the reactor must have weighed less than that.

The 10MW version of SSTAR was supposed to weigh 200 tonnes, 50kW/tonne, while the 100MW version was 500 tonnes, thud 200kW/tonne: https://en.wikipedia.org/wiki/Small,_sealed,_transportable,_...

A 4.95-kg americium thermal reactor design outline has been published: https://www.researchgate.net/publication/239521070_The_Small...

Arleigh Burke class destroyers have 80MW of propulsion and displace 8300 to 9700 tons, compared to which the SSTAR's 500 tonnes is almost insignificant. So weight isn't an issue for ships, and weight doesn't get ridiculously high until you're down below the megawatt scale.

So, you may be right that existing proven reactors won't scale down to a single truck or tank. There isn't a known physical reason it's impossible, or even impossible to do safely, but it hasn't been achieved.

Probably you are right that many small reactors would be more dangerous, but warships exist so that they can go into dangerous situations. You have to weigh the risk of a reactor problem against the risk of being unable to fight because you have no fuel. And we've certainly seen that many militaries have little concern for sailor safety.

Despite all this, no navy has switched all their ships to nuclear fuel. The only explanation I can come up with is that it's unsustainably expensive.

It's not minor at all. For a ground-source heat pump to work at all, you need to sink the pipes deep enough that the soil temperature is pretty stable year-round, which means the heat it can exchange with the aboveground air is minor or insignificant. So the vast majority of heat flux into or out of that soil is due to the heat exchange fluid circulating in the pipes.

After a few years of pumping heat out of the ground below the frost line during the winter, they'll freeze the ground solid and stop working (and possibly destroy the foundation of the house in the process, since often the pipes are installed in trenches around the house).

The only exception is if they're one of these few borderline systems that drill so deep they really are bringing up fresh energy from the depths, like some of the systems mentioned in the article.

Forever is a long time.

Solar doesn't? As far as I know the process for mining the panel and batteries is the same sulphuric acid process with extremely toxic tailings. And you get uranium in this process of rare earth mining. These toxins are orders of magnitude greater in risk and in volume/ quantity than process's nuclear fuel waste.

Ground source heat pumps as used for heating buildings source their energy from the sun and work very well. They are outcompeted by air source heat pumps despite better efficiency because digging is expensive.

I pay 21 cents per kWh and only 11% of my grid is nuclear.

Its funny how mass transit was once seen as a way out of the crisis of too many city horse carriages and all the manure they produce. Metro and rail was simply considered the natural solution, which combined with denser living space allowed for labor intensive industries to sprout up around cities. But then came the horseless carriage and suburbian sprawl became a thing and now we have too much of that. Too much hardened soil and flooding is becoming a much bigger problem, animal and insect populations wither, road networks have upkeep, transport and storage costs make everything imperceptably more expensive. In my scifi fantasy future vertical farming will become a thing which should allow a major shrinking of hinterlands around dense population areas, though preferably not replaced with suburbia. Maybe we could go live in the clouds too.

The US Navy doesn't build them, private companies do. None of the SMR companies that I am aware of have attempted to use designs from naval reactors. Perhaps it has something to do with the fact that they use highly enriched fuel which is a no-no for civilian reactors.

In any event, if your more general point is that naval reactors indicate its possible that SMRs can be built on time and budget, I don't disagree. It certainly is possible. NuScale was the furthest along of the SMR companies and had their project implode before it got off the ground. So, its also possible for them to crash and burn.

So, I'll stick with my classification of SMRs as "maybe it will work out, maybe not".

Showering in hot water is one of the more energy-intensive things people do on a daily basis. I have a 14.4 kW on-demand heater that just barely keeps up with a 1.5 gallon (~6 liter) per minute shower head with 50°F/10°C incoming water.

On a per-minute basis that's comparable to highway driving in a smallish electric car.

As I understand it, no, they do not source their energy from the sun. You have to bury the pipes below the frost line. In temperate climates, the frost line is the place where the earth is so well insulated from the surface by the thickness of earth above it that heat conduction is insufficient to freeze it throughout the entire winter. The sun only heats that surface by radiation.

See for example https://igshpa.org/igshpa-blog/cold-climate-ground-source-he...:

> Unlike air-source heat pumps that struggle to extract heat from frigid air, ground source heat pumps tap into a remarkably stable heat source: the earth itself. Below the frost line, ground temperatures remain relatively constant year-round, typically between 50-60°F (10-15°C). This consistency makes ground source heat pumps highly efficient even during the coldest months.

If you were building a ground-source heat pump to heat your house in the summer, you could get away with burying the pipes at a much shallower depth and in effect converting the earth into a low-temperature passive solar collector. But generally people want to heat their houses in the winter instead.

they're in big concrete containers rated to withstand everything its fine