Gas or heat pump? Experiences / Feedback

Well, you can surely provide the long-term studies on this(?).

I cannot provide a study. In fact, I have heard this several times from the installation companies. If I am not mistaken, I have also read somewhere about a lifespan of 15 years.... Yes, you can now argue that I cannot prove it, and you would be right.

Regarding the CO2 tax: that is, of course, an interesting point. Is there any reason to seriously consider it?

Always just advertising for photovoltaics yourself, but portraying the statements of others as false without arguments.

I am neither advertising photovoltaics nor portraying anything as false. I said one is my opinion and gas is his opinion.

Yes, you're suggesting that now because that's what you have!
But if a gas connection is available, then add solar: cheaper and more comfortable

Thinking about that only starts when gas is not possible.

That's true, I spent a long time dealing with it before building the house and believe that it is the best solution (for my conditions). Gas is also available in my street.
No one is helped by slogans like "Nothing but gas."

It's nothing new that installers say things like "Gas, we've always done it, the new stuff is no good" – you can apply that to all trades, especially when the installers are a bit older.
Heat pumps only made their "breakthrough" in Germany about 15 years ago, and since then the technology has developed by leaps and bounds. A statement about durability is therefore not reliable.

I can only agree with Lumpi on this...such slogans make no sense in a discussion forum. I would also not presume to say that the combination of heat pump and photovoltaic is the miracle cure.

I can only share my experiences here: We built with an air-to-water heat pump in 2017 and retrofitted a photovoltaic system with 8kWp last year and are very satisfied with the combination. Currently, we have a monthly electricity installment of €153. This includes the entire electricity consumption including heat pump + controlled residential ventilation. We receive €74 feed-in tariff from the grid operator. So there are €79 electricity costs/month remaining. Additionally, we consume on average 30% of our produced electricity ourselves in the household. Of course, the high acquisition costs of a heat pump must be considered against that. How long the heat pump will run remains to be seen. However, I do not believe it will be "scrap" after 15 years. Certainly something can break down, but things can also be repaired or replaced.

If I had had the choice back then (budget was limited), I would have had a brine heat pump installed as well. They are even more efficient.

For us, however, the environmental aspect was also one of the main arguments for a heat pump and against a gas boiler. I want to contribute my part to the energy transition and am also willing to pay more for it (if it should be so).

My wish would actually be a battery to store the surplus energy during the day and use it in the evening/night to reduce grid electricity consumption to a minimum. However, batteries are not really economical yet, plus batteries do not look really good in the life cycle assessment either....

We receive 74€ feed-in tariff from the grid operator. So, 79€ electricity costs/month remain.

Don’t you have to pay taxes on the feed-in tariff?
Which often causes only half of it to remain?

Regarding the CO2 tax: that is of course an interesting point. Is there any reason to seriously consider it?

No, not really, that is a figment of imagination.