Electricity consumption at home, what is your consumption?

It only pays off when the heat pump breaks down and needs to be replaced. With the LWWP, you then pay for a new source (outdoor unit), while the borehole remains and does not require a new investment. And, as has been discussed often enough, it depends on the concrete price of the borehole vs. the subsidy you would not get with an air-water heat pump. For us, the additional costs were very manageable and there is no outdoor unit on the building.

The year is over, I read the meter readings earlier. The heat pump consumed around 2400 kWh in 2020. 200sqm, four people. The annual performance factor is 4.29 - there is still room for improvement. Household electricity 3700 kWh. 30% was covered by self-consumption from the photovoltaic system.

Our consumption in 2020:

Total: 8464 kWh
Of which consumption of the brine heat pump: approx. 1800 kWh
Annual performance factor incl. hot water: 5.3
Our house has approx. 160 sqm living space (KFW 55 house).

Please do not confuse ring trench collectors with geothermal energy.

I did not speak of ring trench collectors – but hey... with that, it even comes under the described 2000 €.

Geothermal energy always implies deep drilling for me, and that easily lasts 50 years, sometimes significantly longer. Ring trench collectors and such with own labor obviously look better. But still completely unprofitable.

"But still completely unprofitable."

Such a blanket statement is simply wrong.
I already laid out the calculation above for you.

Because even deep collectors or system collectors (vertical slinkies or in an inclined pit) you can get WITHOUT own labor at the conditions I described above of about 4000 €.

Of course NOT from the heating engineer, who only ever installs and sells air heat pump solutions.

Ultimately, everyone can calculate for themselves what is long-term cheaper including subsidies, etc. (also for the environment/noise).

"completely unprofitable" – as you claimed – is nonsense anyway!

see also here:

It pays off at the latest when the heat pump breaks and needs to be replaced.
With the air-water heat pump, you then pay for a new source (outdoor unit), while the drilling remains and requires no new investment.

And, as already discussed often enough, it depends on the concrete price of the drilling vs. the subsidy you would not get with the air-water heat pump.
For us, the additional costs were extremely manageable and you have no outdoor unit on the building

The annual performance factor is 4.29 - there's room for improvement.

Yes, there is room for improvement. A well-adjusted modulating air pump can definitely keep up. Play around a bit with the parameters to optimize your system...

at night -10° and during the day -2° we currently need 25 kWh in 24h according to the heat pump meter. For a bungalow with 125m2 I find that ok