Geothermal Energy

[RJM Corbet]

Using superheated water from 3.5km deep to generate electricity (9 min)

 

[Boneman]

Fascinatinh Wonder why they don't pass the pressurised water coming up through turbines on its way. Or do they have to pressurised the pipelines down to bring the water up?

 

[CupofJoe]

I think it might be the salt. It would almost certainly gum up if not actively erode any halfway efficient turbine.
Iceland has been using geothermal for years. Admittedly there it is pretty much at the surface compared to the 3500m depth mentioned here.
There are those that are against it on similar grounds to Fracking.

 

[Pyan]

Southampton leads the way! We've had a geothermal station, the only one in the UK, here since 1986...

Southampton District Energy Scheme

 

[.matthew.]

This is a good one about it as well.

 

[Matteo]

There's been a project down in Cornwall for some years also - using the radon/radioactive hot granite.

Some years back I went down South Crofty mine and the temperature was very hot at the bottom (365 fathom I think). There was ground water coming out of the rock that was too hot to touch.

 

[RJM Corbet]

This is a good one about it as well.

It is good.
I like the giant Tesla battery farms!
Geothermal is a reliable source for non-carbon energy, unlike wind and solar, imo?

There's been a project down in Cornwall for some years also - using the radon/radioactive hot granite.

Some years back I went down South Crofty mine and the temperature was very hot at the bottom (365 fathom I think). There was ground water coming out of the rock that was too hot to touch.

There's a disused uranium mine closer to where I am in Devon, that is too dangerous to enter without protective gear.

Kingswood Mine, West Buckfastleigh, Teignbridge, Devon, England, UK

The Bowerdon adit was driven in 1918-20 with pitchblende being reported. It has very high levels of ...

www.mindat.org

A bit off topic, I know, lol ...

 

[JohnM]

The further one goes underground, the higher the temperature. This sort of technology cannot have broad application until investors quietly move away from oil and coal and put their money in this. Until then, oil and coal will remain.

 

[.matthew.]

Coal will remain a popular choice for many more decades. It might be phased out of certain parts of the world but it is incredibly economically efficient and not dependent on the local area - remember than many countries are so large that a single grid is difficult to maintain.

New coal power stations pop up all the time (a couple a week in China alone) and while Covid has caused a massive halt in worldwide construction of new plants, the capacity to build renewable facilities on the same scale isn't here yet.

The chances are that once the world bounces back from 2020, coal will keep right on trucking, albeit not as heavily as it was beforehand.

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Oil on the other hand is here to stay. It's just too useful. Lithium-Ion batteries have an energy density of at MOST 0.9 MJ/kg, while crude oil has an average of around 42 MJ/kg and refining it into petrol ups that to 46 MJ/kg. That's over 51x as much energy by weight. Now, that doesn't mean everything as the efficiency of extracting and using that energy comes into play, but right now it's still a hell of a lot more efficient to power a car with petrol than rechargeable batteries.

Also, consider that even if a battery can be recharged from renewable sources, the battery itself takes a pretty high toll on the environment, and even the money you save on petrol is balanced by the need to replace the battery as it loses capacity. Now, the cost of batteries is getting cheaper, but that is due to production outstripping demand. If every car on the road was electric, we'd suffer shortages of raw materials, much as we feared with oil.

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I do think geothermal is the way forward for powering a grid though, especially if it's as interconnected as many economically developed countries.

 

[Boneman]

Silly thought, but environmentally, if geothermal were on a massive, massive scale worldwide, would that help with cooling the core...? Less volcanic eruptions...? (Old faithful running out of steam?) Just a thought.

 

[CupofJoe]

The effect on the core would be immeasurably small. It is really hot in the centre of the earth and the pressure incredible. There may be more small seismic events as the rock around the geothermal system has to be broken to let the water flow. Or at least that is the argument that is put forward by some.

 

[Alex The G and T]

There's one spot in California that has had highly successful geothermal power plants for 50 years.
Also, A delightful resort to go for bathing in naturally hot mineral waters and wine tasting.

Nothing near so deep as the OP; it's au natural.

News to me, googling around, the power powers that be have revitalized the depleting natural steam reservoirs by injecting wastewater from towns and a city 60 miles away.

The Geysers - Wikipedia

en.wikipedia.org

This one's breathless Corporate PR; but amongst the hyped BS are a few interesting facts.

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geysers.com