Emeritus Prof Christopher MayFeb 26

How big a role can geothermal energy generation play in the UK's green transition?

Well, a new plant coming on line in Cornwall will test that proposition, as its major up-front investment starts to pay off in energy generation.

Of course, we're used to big up-front investment(s) in nuclear power, so it will be interesting to see how this project compares in cost recovery terms & longevity of production.

#geothermal #GreenTransition #energy #politics

https://www.bbc.co.uk/news/articles/cewzg77k721o

Earth's heat to produce electricity for homes in UK clean energy first

Water super-heated by rocks will also provide the UK's first domestic supply of the critical mineral lithium.

BBC News
Show threadPeter Bloem

@ChrisMayLA6 David MacKay discusses this in Sustainable Energy without the Hot Air, and it's pretty disappointing (for fundamental rather than technical reasons). The UK can get at most 1.6% of its energy budget from geothermal.

If you divide the amount of heat the earth dissipates by the number of people, the resulting number is simply pretty low.

It works for places like Iceland, because a large area's worth of heat comes out at one point where the population is low.

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

Feb 26 at 8:36amWeb
Show threadThe Penguin of EvilFeb 26
@pbloem @ChrisMayLA6 the numbers change the deeper you can get but agreed - without a lot of fancy new technology it's just a useful sideline
Show threadBruno NicolettiFeb 26

@etchedpixels @pbloem @ChrisMayLA6 The fancy new technologies are being worked on and are starting to deliver. eg: Fervo Energy is drilling wells down to 5000m and 250C and has working power plants. Those depths open up huge areas for exploitation with minimal surface foot prints. You can even use such wells to store excess renewable energy by shutting off the generator but driving the return pumps to pressurise the wells.

https://fervoenergy.com/fervo-energy-pushes-envelope/

Fervo Energy Drills 15,000-FT, 500°F Geothermal Well Pushing The Envelope For EGS Deployment - Fervo Energy

HOUSTON, TX (June 10, 2025) – Fervo Energy today announced the successful drilling and logging of its Sugarloaf appraisal well, an operational achievement

Fervo Energy
Show threadEmeritus Prof Christopher MayFeb 26

@pbloem

But I guess the one good thing is it doesn't vary so could help (albeit only a little) deal with troughs in other renewables?

Show threadEarth NotesFeb 26

@ChrisMayLA6 @pbloem Un-correlated (including always-on) low-carbon electricity sources are good. Demand-callable / load-following is better, but there are far fewer of those (no GB nukes for example).

(This is 3MW out of ~40GW yesterday's GB peak demand, and there seems to be scope for ~2 more of these cf *20,000* needed to cover *current* peak winter demand in the UK.)

Show threadwill_shakeFeb 26
@pbloem @ChrisMayLA6 so thermal may not be useful for the whole of the UK, but if the economics stack up locally for this project it's a long term climate friendly source of heat and electricity.
And there's experience and understanding to be gained.
Show threadMidgePhotoFeb 26

@pbloem @ChrisMayLA6
1% here, 1% there, adds up.
It looks like power that can be all the time, and/or can be throttled, and should just run and run.
And a few jobs locally where a few jobs helps a lot.

Little tidal projects seem worth it as well.

Both would make more difference to a dunkelflaute than to the ordinary supply.

Show threadQuixoticgeekFeb 26
@pbloem @ChrisMayLA6 this is the case if you're trying to generate electricity from geothermal. But if you instead try to use it for space heating, then a lot more of the UK has geothermal availability. Big heat pumps fed into district heating systems would be a great way of using geothermal and improving the livability of UK homes. And about ~20% of emissions are from heating/cooling buildings.