Why isn't everybody always talking about Geothermal energy? It seems to be the most sustainable and renewable energy, that also never stops working like solar at night and wind when there is no wind. Am I missing something? I just learned my state, California, produces only 4% of its energy from this energy source. Is it money? Or something else?
Geothermal is about 20% of the generation mix in Iceland... where conditions for geo are as close to optimal as anywhere on earth, and the overall mix is very close to 100% renewable. That should tell you about all you need to know about what we should expect in other places. There are just a ton of challenges for geo, siting, stand-up cost, maintenance cost, scaling, transmission, risk of catastrophic loss, ect, and it's not that other means of generation don't have those issues but geothermal just has a really full bouquet of them. I think of it as being pretty analogous to nuclear personally.
"Enhanced geothermal systems" (EGS) fix almost all of those problems. Fracking technology (surprising) is delivering huge wins for carbon free electricity.
“What has fracking ever done for us!”
“Oh, well… there’s that…”
I wish this was more than three DOE demonstration projects, and I hope this technology can make geo more competitive, it would be a welcome addition to the mix
EGS is still very experimental. We don't know if it will fix these problems or if it will have other problems of its own.
Enhanced geothermal systems (EGS) are going to be huge, but most people can’t see a winner for what it is until it’s already won.
also, highly dependent on local geology,
Which is not applicable in most areas of the world. Especially for electricity generation. Solar and wind are simply too cheap and too fast to install.
“EGS” refers specifically to the latest generation of geothermal technologies which are much much less limited by geology.
https://www.energy.gov/eere/geothermal/enhanced-geothermal-systems
I know,I have worked with it is still highly limited by geology.
You can enchance the permeability of some sedimentary layers, but it does not help with unweathered bedrock. And in a lot of the world, the thermocline for temperatures useful for electricity generation is well into bedrock.
Enchanced Geothermal, does open up a lot more areas for district heating, but the temperature required for heating is significantly lower than for electricity.
This person knows geothermal.
Isn't geothermal kinda selective? I'm pretty sure that it needs to be in very specific locations in order to be actually effective (like near geysers or volcanoes or something? I could be wrong idk)
Geothermal energy generation, yes, requires a lot of heat close to the surface and that's selective. Cool where it works, though
A whole other ecosystem of activity, which is also grouped under "geothermal" but doesn't focus on energy generation so much as energy transfer, is much more widely applicable. Sticking a rod full of fluid in the ground under your house with the top going up and touching your heat pump helps equalize the temperature inside your house with that of the ground, leading to cooling in the summer and heating in the winter. It's not actively generating energy, but it leads the the need for less electricity in your house, so very much a great thing.
You can get a lot of energy from those types of locations but normal geothermal can produce a lot of effective heating and cooling from regular soil as long as you can install a system below the frost line to get a consistent temperature of about 4°C.
We should have two different words. There is "geothermal" that creates steam for a generator turbine. Then there is "geothermal" where you store heat in the rocks under your house.
Isn't geothermal kinda selective?
This is a fascinating topic.
First:
Electric power generation from geothermal
This is hard to achieve in most locals because the areas of interest lack the reliable access to enough heat to generate steam, to spin a turbine. But in areas where it is viable, great. But also these should be developed into rapidly-deployable/movable structures because these areas often, shift.
Second:
Geothermal heating/cooling
This technology would save....so much on fossil fuels. The downside is the appliances and infrastructure needed to stand up these technologies. They usually start with either a geothermal well being drilled, or some kind of subterranean heat-exchanger.
Either of which are viable around most of the world to provide heating and cooling to a nominal temperature.
Basically 8-10ft down into the ground, the temperature of the ground stays relatively constant. So if you're able to have enough thermal mass to exchange with, you can heat, or cool to that nominal temperature (in my area that is 45-50 degrees, which is significantly warmer than the -20F it can be in the dead of winter. Then having some kind of heat pump heat the last 10-20 degrees makes for a much more thermally efficient system. Big difference from heating from 45-to-70 than -20-to-70.
Ideally, we could dig a system of wells for a given population, and have a public infrastructure for heating/cooling basics like this. This becomes pretty tricky at super large scales, because humans have such high density of populations, now. It would work at smaller scale though.
FYI the second more accurately called geo-exchange. Particularly in cooling mode, the earth is just a massive heatsink. The energy being used to power the heat pump comes from elsewhere, including possibly solar!
The ground can be used as a thermal battery, too - heat pumps don’t need to be involved. Drake Landing Solar Community, in Alberta, Canada, is a fantastic neighbourhood-scale project that uses solar thermal collectors to capture heat and store it underground for re-release in the winter.
Geothermal energy doesn't just include electricity generation. Every watt of heat generated by a ground source heat pump is like 4 watts of electricity that didn't need to be generated.
That is any type of heat pump.
With geothermal you are pumping against 5 to 10 C (depending on ground temperatures) A standard heat pump has to pump against the outside winter air.
The main detractor as others have stated is that its very dependent on location. This is just due to its technological maturity. We cant dig down deep enough to access the really hot sources in most areas of the world. Fortunately that looks like its beginning to change. There are several companies (https://www.quaise.energy/, and others) that are looking into new drilling technologies to get to some staggering depths.
There are some issues with it, one is that there can be a lot of maintenance and sulphurous waste from the underground water. The hot water with lots of minerals tends to corrode all the pipes that are used. Another is that it actually using similar techniques to fracking and so can have similar issues (although with less poisonous chemicals). As such you have to choose your locations carefully.
Personally, I think it is really great for places where it is available like Indonesia which relies too much on coal. Kenya has gone big into geothermal as that "baseload" power to pair with cheap solar.
Allegedly they die out at some point so it’s not wise to restructure society around them long-term.
It’s not that it’s so expensive as much as that other stuff is cheaper. Same with desalinization in Cali, it’s a proven technology, but it won’t be implemented on a large scale until they have absolutely exhausted every naturally occurring fresh water source, because they are cheap or even free.
Here in my country (New Zealand) we have massive geothermal power plants around our super-volcanoes.
The only flaw with Geo is that it produces a bit of Co2 (much less than fossil fuels though)
The Punk Question: Is it something on the scale of individual or community action can effect?
The technology coming up seems derived from fracking, and so seems more corporate/state scale enterprise...not so punk.
edit: am not sure if I have been shadowbanned or somesuch, But I cannot see all the comments which appear; I do not disagree with what little I can see. I am not anti-geothermal; and I understand the scaling issue of adopting new technologies. I do feel there are better forums for general renewable technologies and for big and small climate solutions. I would like r/solarpunk to stay focused on what individuals and communities can do without the direction of capital and state.
And to answer another commenter's response I can't see, hand made solar cells are possible.
Do you think that people manufacture solar panels in their backyard?
You can make a solar heating device using beer cans and salvaged window glass. Cut the tops and bottoms of the cans and paint them black. It is similar to a Trombe wall.
maybe someday
Let me answer your question with a question: are hospitals punk?
You could communalise healthcare into clinics, which can deal with medical based problems but anything that involves surgical or radiological solutions requires specialist skills and technology simply not achievable to every community.
I don’t expect every village to have geothermal energy but centres of engineering that need moderate power loads and have the talent, it’s a fair solution.
Optimum efficiency of scale is a moving tech-development target; which will prove a constant challenge in the pursuit of ancom/solarpunk ideal.
Hospitals as practiced today in the US are very not punk.
AI pundits such as David Shapiro expect AI will be doing interesting things to bring down the costs of medicine and hopefully decentralize this service.
Sorry for delayed response, reddit is acting weird for me on this thread (or I have been shadowbanned or some such).
Geothermal power in Italy at Larderello has been in use since 1905, well before fracking. That one site produces 10% of the world's geothermal, but it's in a valley with active geysers etc.
If anything, fracking derives from geothermal.
Also, you can have "cooler" geothermal, by using underground aquifers for heat exchange. This can be done on a community basis (with technology of course) and can power space heating for an entire town the size of Reading or Cardiff
See for example the following for an open loop heat pump system based on an aquifer https://www.sciencedirect.com/science/article/abs/pii/S0048969719337957
Similar studies have been done on the Chalk Aquifer in Reading, UK, but over a closed loop system. This was a doctoral thesis which is not easy to find online.
This other paper proposes a tool to check if aquifers are suitable for this kind of work https://www.lyellcollection.org/doi/10.1144/qjegh2014-050
The point of solarpunk is to use technology to enhance communities, autonomy and human freedom and dignity, not to DIY everything all the time.
We are interested in science fiction, social movements, engineering, style, and anything that inspires a future society that is just and in harmony with its ecology.
Right there in the top right hand corner of the sub.
There's even new tech being prototyped for this field that involve drilling wells for geothermal with FRICKIN LASERS!
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