ᐅ Geothermal Energy: Pros and Cons?

Chris29.2 schrieb:
Then we would have completely different problems. :P

That would be off-topic, and someone would have complained that the thread was hijacked.

Yes, it was probably about a water source... as happened in our neighboring village.
Who would be to "blame" in such a case?

But this heating principle does not tap into a water source...

It uses geothermal energy, which has nothing to do with water sources.

You pump a carrier fluid down through a piping system, it is heated by the warmer ground, and then pumped back up.

There are also water-to-water geothermal heat pumps. In these systems, "warm" groundwater is pumped up on one side, passed through the heating system, and then returned cold to the ground on the other side via an injection well.

To return to the original question: I believe every heating system has its pros and cons. As a layperson, it is impossible to fully understand all aspects, so it is essential to consult a professional planner.

The most important point was actually already mentioned in the second post: careful planning and execution are crucial.

We initially also considered a geothermal heat pump and insisted on deep drilling. However, after calculating the heating load and obtaining a geological survey, we realized that, due to the soil conditions on our property, three boreholes of nearly 100 meters (330 feet) each would have been necessary. We quickly abandoned the idea. The drilling alone would have cost us almost €20,000. The investment could not have been recovered.

Bauherren2014 schrieb:
After determining from the heating load calculation and a geological report that, due to the soil conditions on our plot, we would have needed three boreholes of almost 100 m (330 feet) each, we quickly decided against it. Just the drilling alone would have cost us nearly 20,000 euros. That money is not even remotely recoverable.

In our case, the boreholes are designed for a capacity of 7.8 kW (I don’t remember the exact depth). Two boreholes were drilled. The total cost for the drilling (including brine filling, connection, etc.) was about 7,150 euros. Then the Vaillant heat pump was added on top of that.

chaosandi schrieb:
Has anyone ever heard of a water source running dry after some years following deep drilling?

As mentioned above, this is probably a water-to-water heat pump system. I cannot say exactly what the causes might be.

If the heat demand was calculated incorrectly or the entire system was undersized, the borehole can cool down (at least temporarily).

For example, with my layman’s understanding, I had considered activating the underfloor heating via the geothermal heat pump to dry the screed. The general contractor (GC) advised against this, pointing out that it could lead to “overstrain of the borehole and thus to temporary cooling.” If drying of the screed becomes necessary, it is better to use construction dryers or similar equipment.

The GC said that the borehole won’t necessarily be overstressed, but it’s better to keep the risk low.

If the borehole actually cools down, however, it can regenerate over time. The only problem is when it cools down during winter.

Oh, and if any expert is reading this: I’m just a layperson, so please don’t take some of my wording too strictly.

Regarding the opening thread: When I hear Russia’s gas threats, I’m glad that starting November/December we will be heating with geothermal energy. Although this might still be an overly optimistic calculation, since the heat pump runs on electricity. And where does that come from? Exactly! But I think it will still be somewhat cheaper than conventional gas heating.