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Comment by cesaref | Hacker News Reader

It sounds like geothermal without using the earth as the heat source. What benefits does this have over geothermal, which is proven and safe, and also ticks the 'non-nuclear' box which makes it considerably easier to convince a population to live next door to?

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Two main advantages exist. One is that geothermal is not available everywhere. In some places, wells have to be absurdly deep. (The deepest one in finland is 4 miles deep) Second, the temperature of the nuclear reactor is much higher than the geothermal well, allowing you to get much more energy out of a single bore hole.

There could be a few benefits to what is proposed in the article, here are my semi-educated guesses.

1. Less dependent on local geology. Geothermal wells are well suited for hot, non-pourous (?) geology.

2. Might be cheaper. It can take years to drill the wells for a closed loop system (e.g. Eavor), less for a fracked geothermal well (e.g. Fervo). I imagine drilling a single borehole for this is way simpler.

3. Less water loss. Fracked geothermal well wells can be pretty lossy (20%?). If water supply is an issue your options may be limited.

I would imagine the scale. This would provide much more power compared to geothermal installed in the same square footage.

I read once upon a time that when they attempted to do deep-drilling geothermal, they discovered that the surrounding rock loses too much temperature over a course of just a couple years to be useful. At least at the depths that can be drilled.

You get more dumb money for a new idea, especially if it's something nuclear.

Another issue not mentioned by others is that in some regions, geothermal plants have triggered earthquakes frequently enough to become unviable.

Just guessing here, but I think it would have a much smaller footprint.

Google tells me the largest geothermal power plant is in California and it's gigawatt scale and takes up something like 45 sq miles of space.

The other factor might be location flexibility. You can probably dig a mile down just about anywhere but geothermal needs access to magma chambers. Are those everywhere?

>but geothermal needs access to magma chambers.

No, not really. Geothermal can work wherever there's a big enough positive temperature anomaly in the ground. Rift systems with hydrothermal heat can work as well as regions over a deeper magma plume.

Exploiting shallow magma chambers is only possible in a couple regions like Iceland.

> can work wherever there's a big enough positive temperature anomaly in the ground

And is that in as many places as you can dig a mile down? IS the temperature delta in those places on the same order of magnitude as when magma chambers are tapped? If not, gigawatt scale plants would take even more space, no?

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