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Comment by voisin | Hacker News Reader

Is there a cost effective way that people living on the west coast of North America can use this type of geothermal for energy extraction (rather than the common residential geothermal which is just a heat exchanger a few feet below ground), or is it only possible at utility scale?

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For an individual? Not really, no * . The residential geothermal you refer to is actually not geothermal at all, but more accurately a ground source heat pump which is relying on the fact that the soil temperature a couple meters down is about the average annual air temperature. Actual geothermal-powered applications typically require engineering at depths well beyond the grasp of an individual household, and at costs that almost certainly wouldn't make sense for any reasonable payback period that was only covering household energy consumption.

MIT/INL had a nice overview ~10 years ago[1] on enhanced geothermal systems across the USA. Even the commercial power plants that rely on this type of resource are typically situated only in areas with very nice conditions. You also need to be mindful of the heat extraction over the area underground vs. the natural recharge rate. You can draw down the resource if you don't have a good model of recharge, which is particularly problematic for something you probably want to just run constantly once in service.

* Obviously, it is possible for there to be exceptions based on extremely fortuitous resource access (in terms of both the heat and personal capital), but for almost everyone this isn't going to be the case.

[1] https://energy.mit.edu/wp-content/uploads/2006/11/MITEI-The-...

I understand that this is a libertarian place that dislikes the idea of shared-anything in society, but some things really are handled better at scale and this is one of them.

Both turbines and drill shafts have positive returns to scale, so unless you're living somewhere where the hot rocks are very close to the surface this is not practical.

The town of Klamath Falls, Oregon has many homes heated with Geothermal Energy. Its dirt cheap once the well is drilled, just need to run the recirculating pump. The University (Oregon Tech) is completely powered (and heated and cooled) by geothermal, and sells extra power to the hospital next door. The town itself heats many sidewalks and buildings with Geothermal. But to do that, you need hot temperatures relatively near the surface. drilling gets expensive the deeper you go.

One of the best things that could come from geothermal in CA would be the steam that, after going through all turbines, could condense into clouds and rain back down, hopefully somewhere it's needed. It could also power some coastal desalination plants (even though probably wind is better for that - geothermal is great for base load).

Earth doesn't have a lack of clean drinking water problem. We have a lack of cheap clean energy problem.

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