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What it will take to unleash the potential of geothermal power? (2021)

technologyreview.com

31–40 of 108 posts

Re: What it will take to unleash the potential of geothermal power? (2021)

#31
I used to worry that might cool down the earth’s interior too quickly and regret it with mass geothermal.

But waste heat (not global warming from carbon, which is a separate and more pressing problem) will boil the oceans in a few hundred years on our current trajectory, and now I’m for cooling as much as possible however we can.

Re: What it will take to unleash the potential of geothermal power? (2021)

#32
post #7

> They require more capital investment than solar or wind projects: $3,000 to $6,000 per kilowatt, compared with $1,700 to $2,100 per kilowatt for wind and solar. (However, a geothermal plant will produce between two and four times as much electricity as a wind or solar plant of the same capacity.) Solar/wind: 1.7k - 2.1k / kW → N Geothermal: 3k - 6k / kW → 2N - 4N Looks like an investment no-brainer.

I don't understand what that second sentence means. What do they mean by "capacity" if it's not electricity generation capability?

The napkin math factor I use is to get the average power you need to divide solar and wind's name plate power by about 4. So to get the same amount of total yearly energy as a 1GW nuke plant that runs 24/7 you need 4GW of solar. Because solar produces about 6 hours of power per 24 hour day.

From a capital cost perspective this is not nice at all. Too be fair upside of solar/wind is solar and wind farms don't go down for a year and a half of unplanned maintenance like nuke plants sometimes do.

Re: What it will take to unleash the potential of geothermal power? (2021)

#33

This interview with Fervo CEO Tim Latimer on the Volts podcast was really fascinating: https://www.volts.wtf/p/enhanced-geothermal-power-is-finally As a layperson I was certainly impressed by the notion that enhanced geothermal could get us the last x% of firm energy needed for a stable grid once solar+wind+batteries have gone as far as they can go. Another interesting tidbit is that you can actually use their system…

Once we have plenty of solar and wind generation capacity built out, it will be time to start building out short-term storage. Until then, generating capacity is the best place to put capital. In time we will have tropical solar-powered ammonia synthesis, to ship to places that are in danger of draining short-term storage or are in polar night.

So, "as far as they can go" is meaningless. They can go the whole way.

Re: What it will take to unleash the potential of geothermal power? (2021)

#34

I used to worry that might cool down the earth’s interior too quickly and regret it with mass geothermal. But waste heat ( not global warming from carbon, which is a separate and more pressing problem) will boil the oceans in a few hundred years on our current trajectory, and now I’m for cooling as much as possible however we can.

Apparently it could actually be beneficial to cool Yellowstone and prevent it from becoming active again.

Re: What it will take to unleash the potential of geothermal power? (2021)

#35
post #15

I worked on a mining project years ago where we had to dewater the mine of 90 degree Celsius water at 700L/s. Always wondered whether we can use it for energy….

You could use it for district heating of buildings in winter, but that's about it. As the article mentions, you need to get above the phase transition between liquid and gas at high pressure (they mention 150c) to be able to reliably and quickly convert the thermal energy into kinetic, then into electrical inductance (gas expansion moving a turbine, moving a dynamo). Maybe if you went into business making pot roast,…

There are fluids other than water that have usefully different boiling points.

Problem is that mature turbines are designed for steam. Turbines for other fluids cannot approach their market volume.

Re: What it will take to unleash the potential of geothermal power? (2021)

#36

HVAC geo scales up. You could do a neighborhood utility and homes can heat/cool for the cost of air circ. You'll wind up with a novelty, an HOA that benefits every home (fees for for power/maint pumps). A couple of generations ago, we had neighborhood sewage utilities all around here. Neighborhood geo seems less complex than that.

This was tried using money for 2010 olympics in Whistler BC as the athlete accommodation was sold as subsidized housing to local workers after the olympics. The geothermal district heating project had many ongoing issues with repair costs being borne collectively by the new owners. Some saved $150/mo by removing it and switching to electric [0] 0: https://www.piquenewsmagazine.com/opinion/letter-to-the-edit...

I appreciate the info. I'll give it a read.

Re: What it will take to unleash the potential of geothermal power? (2021)

#37
post #32

Earlier quoted context omitted.

I don't understand what that second sentence means. What do they mean by "capacity" if it's not electricity generation capability?

The napkin math factor I use is to get the average power you need to divide solar and wind's name plate power by about 4. So to get the same amount of total yearly energy as a 1GW nuke plant that runs 24/7 you need 4GW of solar. Because solar produces about 6 hours of power per 24 hour day. From a capital cost perspective this is not nice at all. Too be fair upside of solar/wind is solar and wind farms don't go down…

Wind is rather better than 25%, most places where it is used.

Re: What it will take to unleash the potential of geothermal power? (2021)

#38
post #15

I worked on a mining project years ago where we had to dewater the mine of 90 degree Celsius water at 700L/s. Always wondered whether we can use it for energy….

Sous Vide is 50-60'C?

I use to scoff, but turkey sous vided is yummy

Re: What it will take to unleash the potential of geothermal power? (2021)

#39

I used to worry that might cool down the earth’s interior too quickly and regret it with mass geothermal. But waste heat ( not global warming from carbon, which is a separate and more pressing problem) will boil the oceans in a few hundred years on our current trajectory, and now I’m for cooling as much as possible however we can.

Wow. Have you got a source for that? Waste heat from human power generation and use, not from the Earth cooling? Boil as in bubbles of steam or just slightly evaporate a little? A few hundred as in < 1000 years? And current trajectory as in something like exponential growth which obviously won't happen? I'm sure some part of that makes the idea far less serious than it sounds.

Re: What it will take to unleash the potential of geothermal power? (2021)

#40
post #27

Make drilling cheaper. This would also help with water access. The biggest cost of small geothermal and water projects is always the drilling. Drill rig time is always a limiting factor.

> Make drilling cheaper. How?

I've been wanting to build and try something like this:

https://youtu.be/3pOSzBgB8WU?si=kCyDZA0GkKMFAzNH

Could easily be improved upon, seems workable

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