Which heating system for the 200 sqm new building?

The political development has probably passed you by recently as well, but just keep dreaming of your so great return that doesn’t exist. You won’t even get a positive return with a ridiculous 12-cent feed-in tariff, self-consumption has to be added. And if electricity gets significantly cheaper, your calculation is wrong. No one guarantees that to you either. Thanks to the heat pump tariff, I pay significantly less for electricity than usual and that without slapping such a thing on the roof with all its disadvantages

You won’t get such returns anywhere for a 100% secure investment, purely from feed-in. What is ridiculous about 12 cents? The statement makes no sense without context. It’s like saying 1€ for a kWh of electricity is ridiculous. No one claims you can’t earn more with stocks, but that’s not secure, many have already destroyed their lives with that. Heat pump tariffs make no sense in 90% of cases, but that’s how you can also fudge the numbers a bit. Political development is currently, if anything, trending green and you’re talking about the end of renewables... One can only shake their head.

I am not talking about gambling on the stock market, where the returns would be much higher; I am talking about Dax ETFs and the like. Over the same period, there is practically no risk. What if your photovoltaic system breaks? Are material defects insured, inverters, etc.? A neighbor just had huge trouble. Where is your 100%? Before you call things ridiculous here, you should inform yourself first.

Hampshire summarized it very well. I don’t think photovoltaics are inherently bad; there are reasons for it. But returns come far behind...

and the energy price development is uncertain because the world will change, predictions are like the weather—rather unreliable.

Many homebuilders consider it and ultimately don’t do it. I am one of them.

Except for the inverter, everything has a 25-year warranty, and a module defect is almost non-existent. What kind of trouble did your neighbor have?

But I also didn’t start with the returns; I would have done it even if it had been a break-even over 20 years. As the system is running, however, it pays for itself in 9 years. I just found it pointless to compare photovoltaics with stocks.

In a decision against photovoltaics, often only unsubstantiated reasons are given, like the one with the 12 cents without any context.

The neighbor had a marten twice, which destroyed the cables each time. Once there was a cable fire because of it. Not funny, even if insured.

We have now been living for one year in a kfw40+ house with an air heat pump (outside), photovoltaics, and storage. Buffer storage at the air heat pump, underfloor heating, central ventilation. We are very satisfied. The air heat pump is super quiet, I have to hold my hand in front of it to feel if it is running. Only in winter at -8 degrees you can hear it from a distance of 5 meters. Net energy consumption after 12 months 822 kWh (2930 consumption minus 2108 feed-in) for electricity, water, and heating. In winter we have 21 degrees in the rooms, in summer outdoor blinds shade the rooms. Today, with 35 degrees outside, it was 22 degrees inside. We could still retrofit the cooling function for the air heat pump.

Oh, important information about my text above
205 sqm living space