Geothermal Electricity ready for prime time.

woodgeek

Minister of Fire
Jan 27, 2008
4,323
SE PA
Another Dave Roberts explainer....


Bottom line, using fracking and water injection technology (rather than just natural hydrothermal sites) we can scale geothermal power production to the level that it could provide most US electricity needs for millennia, as always on baseload power with zero emissions.

Cost per kWh is a strong function of rock temperature AND skill in things like horizontal drilling and fracking large subterranean areas from a single small footprint. The fracking revolution of the last decade has essentially made a vast energy resource potentially affordable. For large areas west of Rockies, the projected price looks quite feasible. Presumably learning curve would bring that down.
 

begreen

Mooderator
Staff member
Nov 18, 2005
87,089
South Puget Sound, WA
I would love to see this happen in our state. Power companies like long-term investments for guaranteed results and the regional supplier is still not sold on geothermal, unfortunately. The risk I have been told is that in an earthquake prone region that there could be sudden changes in the subterranean structure that could dramatically affect output.
 

semipro

Minister of Fire
Jan 12, 2009
3,984
SW Virginia
The risk I have been told is that in an earthquake prone region that there could be sudden changes in the subterranean structure that could dramatically affect output.
or that removal of enough geothermal heat may cause "unnatural" changes in the subterranean structure, I'd assume.
I'm not really a big fan of geothermal energy because I don't see it as renewable and tapping it may threaten other finite resources like drinking water aquifers.
I'd also challenge any notion that our use of geothermal sources won't alter things appreciably. That assumption with respect to other effects is a fallacy.
 

GENECOP

Minister of Fire
Jan 31, 2014
734
Ny
If billions can be made by the powers that control things, it will be exploited to its Max..but I think they want to use up a little more oil first..
 

woodgeek

Minister of Fire
Jan 27, 2008
4,323
SE PA
or that removal of enough geothermal heat may cause "unnatural" changes in the subterranean structure, I'd assume.
I'm not really a big fan of geothermal energy because I don't see it as renewable and tapping it may threaten other finite resources like drinking water aquifers.
I'd also challenge any notion that our use of geothermal sources won't alter things appreciably. That assumption with respect to other effects is a fallacy.
I often felt the same about depletion of the resource, which happens rapidly at natural fields (which can connect to natural aquifers).

The article described the creating of artificial fields inside hot impermeable and dry rock. So at least in principle, not going to affect an aquifer if the wells are sealed.

Roberts also points out that seismically, the volume and pressure of water needed for geo are a lot lower than in fracking for FF, so concerns are less.

Faults should still be avoided, of course.
 

semipro

Minister of Fire
Jan 12, 2009
3,984
SW Virginia
An interesting geothermal solution that uses the thermosiphon effect and closed loops to harvest heat.
I've been thinking for years about doing something similar for roadway deicing and summer cooling. It would be more "ground-source" than "geothermal" though, relying on insolation as the heat source.
 
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peakbagger

Minister of Fire
Jul 11, 2008
6,122
Northern NH
Sounds like the systems the DOE was trialing off Hawaii using the temperature difference between the deep ocean and the surface.
 

begreen

Mooderator
Staff member
Nov 18, 2005
87,089
South Puget Sound, WA
Sounds like the systems the DOE was trialing off Hawaii using the temperature difference between the deep ocean and the surface.
We visited that test project in the 1990s. It was fascinating to see all the different tests that were being done in addition to the small generator project. The spirulina farm using the nutrient-rich deep ocean waters spawned a market for a nutritional vitamin producer locally. My favorite was the student farm where they tested the effect of chilling the soil on crops in their 75-80º ambient temperatures. Brassicas did well, strawberries did ok and corn did poorly. That's not surprising, but it was great to see kids testing this.
 

semipro

Minister of Fire
Jan 12, 2009
3,984
SW Virginia

ABMax24

Minister of Fire
An interesting geothermal solution that uses the thermosiphon effect and closed loops to harvest heat.
I've been thinking for years about doing something similar for roadway deicing and summer cooling. It would be more "ground-source" than "geothermal" though, relying on insolation as the heat source.
We are supposed to have a small geothermal plant (5MW) built an hour south of us, it will be a trial plant for the region. Our major issue is the low temperature of our resources, it doesn't make a very effective steam based plant, so I believe this setup was going to use the organic Rankine cycle.

What would be a huge win for us is the leftover waste heat, and this project proposes to use that for industrial heating.

 
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peakbagger

Minister of Fire
Jul 11, 2008
6,122
Northern NH
We are supposed to have a small geothermal plant (5MW) built an hour south of us, it will be a trial plant for the region. Our major issue is the low temperature of our resources, it doesn't make a very effective steam based plant, so I believe this setup was going to use the organic Rankine cycle.

What would be a huge win for us is the leftover waste heat, and this project proposes to use that for industrial heating.

There was a firm that bet big on low temp geothermal use ORC out in the western US and failed miserably. They didnt spend to the time tot. characterize the resource and install a field of units before they realized that the resource wasnt as good as they thought. My old employer spent a lot of time working with them. https://www.energy.gov/eere/geothermal/articles/construction-underway-first-geothermal-power-plant-new-mexico It burned through a lot of goverment funds before going bellyup.

A resort in AK got a lot of grants to but in a ORC geothermal power plant in the 2005 https://en.wikipedia.org/wiki/Chena_Hot_Springs,_Alaska Pratt and Whitney was developing the equipment and used this place as early commercial installation. I think they sold the tech to Mitsubishi who was partnered with Turboden and Italian firm that does ORC.
 
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