Gas with solar thermal? Or heat pump with photovoltaics? Consultation

Attention, a really serious question. Is the ecological balance of a "wooden house" really better in the long term than that of a stone house? No idea whether concrete is that energy-intensive, but on the one hand, a solid house is only partly made of concrete, and on the other hand, from a layman's perspective, I would think that stone lasts much longer than wood. Really quite naively considered, the pyramids and castles are still standing but pile dwellings or wooden houses from old times are all gone. Once again, a really serious question. We would have liked to have a wooden house, but the costs and expertise of the architect ultimately did not allow it.

If you care about ecology and sustainability, buy an existing property.

Photovoltaics no longer pay for themselves, most systems have to run for 10 years just to earn back the purchase price. If a storage unit is added, you pay on top of that.

To what extent does today's decision affect my modernization options in the future? If I want to modernize the heating in 15 or 20 years, am I limiting myself by choosing between today's options? Or does it not matter?

That is not a problem with proper planning.

I had my underfloor heating designed for 30/23 at 20 to 22 degrees.

So if in a few years gas becomes so extremely expensive that it pays off, I only have to remove the boiler and connect a heat pump.

If you care about ecology and sustainability, buy an existing property.

Photovoltaics no longer pay for themselves; most systems have to run for 10 years just
to recoup the purchase price. If you add a storage unit, you pay even more.

Sorry, that's nonsense. Photovoltaics do pay for themselves; do they just disappear into thin air after 10 years??
What about after 15, 20, 25 years? O.K., storage can be defective (batteries) – replace – done.
Profitability will probably be 2-4% (or more depending on the individual situation).

But I only want to give suggestions and do not want to start a fundamental discussion here.
Everyone should form their own opinion (if they can calculate correctly).

Regarding storage: it's (almost) never economically worthwhile, I completely agree with you there.
And: indeed, the electricity lobby is aiming for "absurd" things. But the 52GW cap hasn't fallen yet, and what will apply next year? I have no idea.

Download the photovoltaic solar irradiation data (understand the system), plan a concrete object – decide.
P.S.: I am a photovoltaic layman, haven’t understood everything yet, but everything necessary for the calculation.

P.P.S. I already have an existing property, otherwise none available to me privately here, and
traveling further (reachable by bike for me) also makes no ecological sense.

An investment that has paid back after 10 years has a return of 10%. And that with 20 years of guaranteed feed-in tariff. Everyone has to decide for themselves, my roof is full

An investment that has paid back after 10 years has a return of 10%. And that with 20 years of guaranteed feed-in tariff. Everyone has to decide for themselves, my roof is full

No: compound interest. 7.18% would be the return if you disregard inflation and taxes. If I have calculated correctly now. Investment calculation was never my strength and I didn't have to do it for 10 years either. Someone can gladly check here.

Still, I think it’s a good interest rate...