When the surface of the ground is frozen, 8' down is above freezing...45 or so degrees. Is that the geothermal energy they talk about? Elon Musk is tunneling into the earth for geothermal energy. Firstly, that doesn't sound "environmentally friendly"......secondly, that would still require more heat for the winter. I guess it would make for good cooling in the summer.......but it would need dehumidified wouldn't it?
Somebody who understands it please explain. I'm an edjit.

i dont fully understand it either.... but it works.... i have friends that heat big shops with geothermal wells 200 ft deep and heat pumps... some how it takes whatever the temp of water is and takes a couple degrees off and bunches it all into heat!! i think its a viable source of energy... spendy up front tho !!

a heat pump is an air conditioner that runs backwards

the issue with them is it starts to get very inefficient below freezing , but if you can keep tapping into 50 degree water it is basically the same efficiency as heating your home to 70 with 50 degree air outside


Geo thermal like they use in Iceland is a tap into a hot spring , like if you pulled the water form old faithful in Yellowstone piped it into the lodge and when it was run through enough heat exchanger coils that it was below or at room temp pumped back out to refill old faithful

I think Musk is trying to drill super deep and super heat the water making steam for the purpose of heating , that requires very little energy

The steam would likely run a turbine to generate electricity. just a guess

They’ll also use the heat to heat another fluid with a lower boiling point that runs through a turbine creating electricity.

I drilled some geothermal wells back in the '80s south of Van Horn, Tx to a depth of around 5500' but don't know anything else about them as I was only involved it the drilling phase.

Built a lot of geo. hog barns back in the day. Useing air drawn down from a distance, then it travels till it reaches ambient temp. About 45 F. That 45 F air takes less energy to heat to 75 F than 20 F air taken from directly outside the building. At least that how geo. works in Indiana. Warming 45 degree air to 75 degrees is cheaper than warming 20 degree air to 75 degrees. Summer, same in reverse. JMO.
Casexx.

Edit to add. Geothermal is different than Hydrothermal.

Thanks, now that you mentioned it, I think the wells I drilled were hydrothermal as the temp at that depth was around 175 degrees.

I think he is digging for high-speed underground transit, not geothermal.

Very interesting responses.....thanks guys. I had no idea you could drill down and find 175* water. I'm guessing that's not found everywhere???
When I worked in the oilfield we drilled real deep but at the time I had no interest what the temperature was down there.

I guess the old swamp coolers were geothermal cooling but without the fancy name. Same with our ancestors digging root cellars to store food in.

Ground temperature below frozen ground is around 55 degrees they tell me. Geo thermal circulates the water and the heat pump only has to use enough energy to pull heat from it up to I think around 80. Then run till your stat is satisfied with your setting. Air to air heat pumps have to pull the heat out of the outside temps. Gets difficult when the temps fall below 10 degrees. That's why they usually run on backup electric heat banks in the furnace when it gets really cold. My geo thermal use to run on below zero nights but as it got older and the ground settled more around the pipes it doesn't have to kick in the backup.

Someone told me that no matter how cold the air is outside.........there are still heat molecules in the air that can be used. I have no idea.

not molecules but energy

and it isn't completely true , well it is to an extend absolute zero there is no heat left and everything is colder than liquid nitrogen , at that temp everything is a solid

since it is more realistically a point of diminishing returns , below freezing your point of return starts dropping quick , by about 10 you would use less electric just powering a heating coil

Your refrigerator is a heat pump. The freon and compressor "pull" heat from your refrigerator and release it into your kitchen. They do the same with water wells etc. . It isnt "free", It does take alot of electricity.

Gotcha. Same with an A/C. Thanks again guys.