"Geothermal" (as they call it here) of that sort can be had in the US, but it's very expensive to install unless you have a large yard (otherwise you have to dig even deeper) and it's difficult to impossible to recover the cost of the system at sale if you move before saving enough to justify the cost—which itself may be difficult if you consider the opportunity cost of the money, and especially if you take out a loan to do it. The buried hoses/pipes also have a limited lifespan, and will need to be replaced in a couple decades, again at great expense.

In short, we don't do stuff like that in the US (at least, not much) because it's often a good way to lose money.

Also, I don't know about Spain, but large parts of the US suffer very high humidity through much of the year. Unless you're on an exposed hilltop with a breeze, it's miserable without good air conditioning. Houses aren't build with cooling-via-open-window in mind anymore, either, having fewer and smaller windows than older houses and being built with no thought to positioning the windows and the house itself such that prevailing winds can blow through it. Many interior materials aren't intended to tolerate even moderate temperature and/or humidity swings anymore, and will deteriorate much more quickly under those conditions. So there aren't many days in a year when it's possible to get by with no heating or cooling and just open your windows, either.

> Have you considered alternatives? My house in sunny Spain spends less than 1Kwatt in August pumping water in a pipeline in the soil that has a big thermal inertia, and small air conditioning units for the air.

Lol, Geothermal costs more than the electricity prices. Geothermal costs $25,000ish. It'd be cheaper to install the Powerwall!

In my state, a kWhr costs $0.08. Large air conditioning units are more efficient. I have a programmable thermostat that keeps the air conditioner off the vast majority of the time.

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The name of the game is to buy big, efficient units. They draw a lot of power while they're on but then they shutoff once your house reaches 76 degrees (or ~24.5 Celsius).

Again, you buy big to be more efficient. We've run the math already. A big efficient whole-house 3-ton AC unit for $1500 is much much cheaper than a Geothermal unit of $25,000.

Then get a programmable thermostat to keep it on only when you need it.

Spain is pretty darn temperate. Average daily highs don't even rise above the 90s in the hottest months. There are a lot of areas in the US that are far hotter, and if you're thinking about taking advantage of solar energy, chances are you're in one of them.