Gas or geothermal energy - advantages / disadvantages?

I am not an expert either, but where did you get this figure from?

Geothermal heat pump with ground probe: 25,000 euros

Our heat pump costs about 10,000 euros (without the materials and heating, which are always needed). In addition, the drilling with a total of 100m costs just over 5,000 euros.
Have you talked to both an installer and a probe driller? Even if you need more power than we do, there is still quite a bit of room to improve.

Our costs for gas connection and gas condensing boiler as an example:

2500 EUR Viessmann Vitodens 200-W
700 EUR Viessmann Vitocell 100-W
380 EUR installation materials
(all net)
The individual requirement for pipes and radiators/underfloor heating in the house is additional, but that is not the point here

1785 EUR gross for gas connection

In total approx. 6050 EUR gross

I'm not an expert either, but where did you get this figure from?

Our heat pump costs (excluding the material and heating system, which you always need) about 10,000 euros. In addition, the drilling with a total of 100m costs just over 5,000 euros.
Have you talked to both an installer and a probe driller? Even if you need more power than we do, there is still quite a bit of room for improvement.

As I said, the values so far have come from my internet research. There I often found about 20,000€. I then calculated a bit higher... better too much than too little. Also because I have already read in other forums about ground source heat pumps with ground probes for 40,000 euros...

Our costs for gas connection and gas condensing boiler as an example:

2,500 EUR Viessmann Vitodens 200-W
700 EUR Viessmann Vitocell 100-W
380 EUR installation stuff
(all net)
The individual need for pipes and radiators/underfloor heating in the house is additional, but that’s not the point here

1,785 EUR gross for gas connection

In total about 6,050 EUR gross

Thanks for the numbers...

For us, the solar thermal system would still be added here... then you would probably end up at about 9,000 to 10,000 euros.

By the way, the new building is supposed to be completely equipped with underfloor heating. Would a low-temperature gas boiler be of any use to me here?

A trench collector could work for you, provided you are allowed to lay the pipes at least straight over the water pipe. It might also be enough to stay on one side, but then the extraction performance will probably be tight.

Google it, the topic is widely discussed on the internet and, with own effort, also cheaper than a surface collector.

The difference to the gas condensing boiler is probably not very big.

A trench collector could work for you, provided you are allowed to lay the pipes at least straight above the water pipe. It might also be sufficient to stay on one side only, but then the extraction capacity will probably be tight.

Google it, the topic is discussed extensively on the internet and with your own effort also cheaper than a surface collector.

The difference to the gas condensing boiler is probably not very big.

What sizing do the collectors have to have? I once read something about twice the size of the heated area..140 sqm x 2 = 280 sqm collector area? On one side, perhaps 140 sqm would be possible with boundary distances... I initially didn’t want to go over the water pipe itself. Since it is also at about 2.00 meters deep.

Hello,

What is often overlooked is that the air heat pump has a similar "service life" as a gas heating system. That means it must be replaced after at the latest 15 years

Where do you get this data from? Heat pumps have not been in use long enough yet to make reliable statements about their lifespan.

Additionally, friends have told us that the air heat pump sometimes does not manage to provide enough hot water for a 4-person household (e.g., when everyone showers one after another after a bathing trip).

Air-to-air heat pump or air-to-water heat pump? What is the storage volume for domestic hot water?

Rhenish greetings