Water-to-water heat pump alternative, or still possible?

Who is spreading that nonsense about the funding? Of course it exists and not even in small amounts.

But not in Austria...

But not in Austria...

Alright, then I'm out.

I wouldn't use a (air) heat pump there either, depending on the climate.

Then maybe good old gas after all?

I don't like the idea of being dependent on a gas source or oil. To be honest, I am considering (when photovoltaic systems and associated accumulators are more developed in a few years) being able to obtain energy almost autonomously. And for me, the heat pump is a conceivable option. I don't necessarily want an air heat pump because there are more efficient methods of operation.
The heating system is (so far) by far the biggest question mark in the construction. What the research, energy, and effort have already cost is actually crazy.