Trench collector brine-water heat pump or air-water heat pump?

570 € is cheap - or rather, it obviously depends on your ground

I assume that is only for drilling - there are quite a few additional costs

All in, we paid 7,126 euros for the entire drilling - at 7.8 kW. Included were site setup including arrival/departure of the equipment, drilling, backfilling, 95 l brine filling, container + removal of the excavation, compression ring seal, connection of the double U-probe, shut-off device of the supply line. With that, all work related to the drilling was covered.

No idea if it is cheap or expensive. It was the company recommended to our general contractor due to good experiences. As far as we can see, they did good work.

I'm just surprised because every ground offers different extraction capacity - also the question of how many drillings.

We will only aim for one drilling and currently expect 140 m, but still have to wait for the heating load calculation.

With the BAFA bonus, the brine drilling really pays off now .

I'm not quite sure - but 120 m was discussed with us at one point.
BAFA funding?
I believe that it is either new in 2015 or it relates to funding for a used property or is regionally specific (NRW - although I don't believe this if it comes from BAFA).

Since April 1, 2015, new buildings are also subsidized with €4500 if they install particularly efficient brine-water heat pumps (annual performance factor > 4.5) or have better system efficiency (no idea what exactly that means - this information is not missing on the Bafa page) Problem is often that certain systems are not on the Bafa list because they are e.g. too new.

We will make the same call on Monday - for an AlphaInnotec system (so far only the previous model is listed).

Report back - although in the end, only something in writing from them counts for me. It's about too much money...

Pump manufacturer: the new pump will be available in June and certified in August Bafa: yes! BUT - one can submit the application with a note that the certificate will be provided later. Payment will then of course be made only afterwards. Additionally, he also recommended a few other things to us: the well builder must be WS120-2 certified and have insurance against drilling damage without deductible. Otherwise, the usual points. We are now somewhat wondering if it is wise to have such a brand new device installed. As is well known, teething problems often occur with mechanical engineers.