Progress in geothermal renewable energy

Investment Analysis Clubs Macro Economic Trends and Risks
1

Combine the heat of your kitchen oven on max (450 degrees Farenheit) with fracking technology and diamond-coated drill bits and what do you get?

Geothermal energy, the ultimate “renewable” energy source. Expensive to set up but the heat source is continuous and free. Not actually “renewable” because the heat has been there since the Earth itself was created. This is solid-rock fracking, not using existing subterranean hot water which is limited in area. It uses nonpotable surface water.

https://www.wsj.com/business/energy-oil/geothermal-energy-commercialization-technology-f2ae267b?mod=hp_featst_pos3

We Finally Know How to Get the One Renewable Energy Source Loved by Both Parties

The question is whether geothermal power, right beneath our feet, can compete on cost and reliability

By Christopher Mims, The Wall Street Journal, Oct. 23, 2025

America has an effectively limitless supply of energy waiting to be tapped, right beneath the feet of hundreds of millions of its citizens.

The equipment required to get at it is almost 100% domestic or comes from nearby allies. And politicians on both sides of the aisle love it, unlike other low-carbon, renewable energy sources. …

Geothermal energy is the only low-carbon, renewable energy source whose generous subsidies in Joe Biden’s big infrastructure bill of 2022 were preserved in President Trump’s “Big Beautiful Bill.”…

Fervo’s current tech can yield a power plant with all-in drilling and building costs at around $6,000 per kilowatt of energy-generating capacity. For comparison, natural-gas power plants typically cost around $800 to $1,000 per kilowatt of capacity to build — but they also come with considerable costs to run, mostly in the form of all the natural gas they burn…. [end quote]

The hot granite underlies much of the western U.S. The fracking can cause earthquakes (like fracking for oil) so the location has to be carefully chosen. But there’s a huge amount of uninhabited land in the western U.S. that doesn’t have (and doesn’t need) oil or gas to use this technology and isn’t near geological fault lines.

I hope that this is developed into a widespread energy source.

Wendy

8 Likes
2

The oil companies wanted those subsides preserved because they are the drilling experts. They plan to be in this area of energy when oil energy has become relegated to the dustbin.

2 Likes
3

This is our local geothermal effort:

The Geysers is the largest geothermal energy complex in the world, located in Northern California’s Mayacamas Mountains. It produces enough electricity to power roughly 725,000 homes by tapping into a naturally occurring underground steam reservoir. The steam spins turbines that generate electricity, providing a reliable source of clean, renewable energy for Northern California.

They pump in local wastewater, and it comes back as steam! Been going on for years, causes some minor quakes, pretty much daily in the area, but the overall is positive… Cold mornings, the steam is visible for miles…

5 Likes
4

That is pure geothermal, and it’s great where it’s great (not where deep drilling or horizontal placement is difficult or schist is shallow). We have geothermal-hvac, a hybrid which brings us water from a simple shallow well.

That water is always 50° to 55° and performs the same function as the big fans outside so many homes: removing excess heat from the system when cooling and/or providing heat exchange when “making heat.”

The difference is that HVAC systems struggle when outside temperatures get low, because finding “excess” heat in 20° air is difficult - but our heat exchanger (ground water) is always higher in winter, and lower than the 90° ambient air in summer.

It makes the system far more efficient; there’s a trade off, of course, it’s more expensive to set up (drill, water charging, pump, etc) but it runs cheaper the rest of its life.

8 Likes
5

One condominium development I am investing in specified an idiot form of A/C, providing one cheap unit for each condo, and two for the bigger ones, of course with ugly noisy fans mounted externally but not shown in the mock-ups. It was amazingly difficult to persuade the developers and other key owners to do ground water heat exchange (we are on a side hill slope with a large continuous flow of cool ground water only three meters down), but I pulled it off via lots of sweet talk mixed with screaming.

Ignorance, stupidity and pretending the long term is irrelevant are the defaults of our culture, but can be countered.

10 Likes
6

We had a recent posting that someone is recovering waste heat from sewage. I see that as an interesting innovation. Requires investment but probably a steady source of energy many places.

1 Like
7

Installation costs are considerably higher with geothermal for HVAC than for traditional heat pump units. Also, that shiny new condenser outside the unit gives all the appearance of warranty, industrial durability and local serviceability.

In summary:

  • Higher initial cost
  • Uncertain (uncommon) maintenance perception
  • Local first-of-a-kind experience for decision makers (higher implied risk by uncertainty)

So, yeah. I’m sure it went exactly as expected trying to counter the above points.

On a broader topic. Low quality HVAC geothermal (ground loop, Aquifer thermal energy storage or Bore hole thermal energy storage) are COMPLETELY separate from HIGH quality geothermal.

Not surprisingly, well costs are highly dependent on location, location, location.

My good friend still runs this site and has been a hydrogeologist for many decades. He consults on projects world wide and is a partner to several consortiums related to study, advancement and completion of utility scale projects in this area.

Underground Energy | Applied Hydrogeology Geothermal Innovation – Applied Hydrogeology Geothermal Innovation

Specific to High quality Geothermal:

In California where the thermal gradient quite steep, a well can reach high quality heat in only a couple hundred feet, the costs to drill and complete the process for high quality geothermal heating measure in the $100K’s range.

In areas where total depths of 5 miles or more is required, that cost is 20-50x. (25,000’ total depth, with completions to fracture)

This is, in addition to, top sides equipment and processing. Steam heat generation with several cascading stages are not cheap at utility scale.

5 Likes
8

The quakes have been occurring for centuries. Pumping waste water did not cause any more quacks. Pumping waste water kept the geothermal water supply from being exhausted.

3 Likes
9

GDavenport,
Thank you for that excellent link.

1 Like
10

The cost of drilling a well for water (as many homeowners already do) is usually between $5,000 and $15,000, with the occasional outlier higher.

My geothermal HVAC (heat pump) models (two of them) cost around $2,500 more than a traditional air-cooled model. So altogether that’s around $10,000-$20,000 “extra”, for which I save about 50% on heating costs and 35-40% on cooling costs (random guess based on current bills) or about $1,500 a year.

For someone already drilling for household water the cost is a mere $5,000 or less. Our well is incredibly shallow, as we live on a riverbank so the water table is very high. Again, deminimus drilling cost.

On the other side of the equation, I live in TVA territory, so electricity costs are quite low. For someone living in a high electrical cost area the economics can be compelling.

3 Likes