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.
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.
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.
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).
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. :)
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.
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.
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.
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".
> 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]
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.
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.
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.
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.
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.
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.
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.
(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 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.
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.
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.
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.
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.
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.
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.
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.
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
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.
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.
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.
> 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?
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.
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.
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.
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.
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.
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.
