Photovoltaic system air-water heat pump - profitability single-family house KFW55EE

And not with +- but against a profitable investment, say 5% per year.

But you first have to find a profitable investment with 5% and the same risk that a photovoltaic system has. But of course, you can always turn the calculation both ways. Sometimes ETFs are absolutely safe, and the solar system lasts 10 years, and another person predicts the ETF collapse while the solar system lasts 30 years... everyone will get the result they want.

I will now also put forward the bold thesis that with the advancing e-mobility and the demand for E-Fuels (Surprise! There are other means of transport besides cars that currently burn dead dinosaurs to our disadvantage), the electricity demand worldwide will increase significantly, and as with all things, at some point the demand for your photovoltaic electricity could tinker with the price, even if the grid operator does not have to buy it from you for more than 6 cents. Then maybe soon someone will come along who offers you a few cents more for it. Or a few cents more than a few cents more.

If I understood correctly, this has probably already been the case for the so-called Ü20 systems in 2021. For systems that are no longer subsidized, some kind of annual average value is apparently determined, which then applies to the feed-in... and in 2021, due to the rising stock market electricity prices, that was indeed already 7.5 cents!

And then there is the uncertainty of the autonomy gap that I have to buy. What does the calculation of a deliberately kept small system look like when electricity prices rise to 50 cents? The larger the system, the smaller this gap, the more relaxed the future. For me, the charm of a monoenergetic house lies in being as independent as possible. I would take every kWp on the roof that fits.

I'm now going to put forward the bold thesis that with the advancing e-mobility and the demand for e-fuels (Surprise! There are other means of transport besides cars that currently disadvantageously burn dead dinosaurs) the electricity demand worldwide will increase significantly, and as with all things, at some point the demand for your photovoltaic electricity could manipulate the price, even if the grid operator is not required to buy it from you for more than 6 cents. Then maybe soon someone will come along who offers you a few cents more for it. Or a few cents more than a few cents more.

I doubt that. If e-fuels come, then as before, it will be managed through an oligopoly like gas stations. That’s the only way you can supply that many people. The existing injection points are already scarce. I fear that except for capping own consumption, private photovoltaic systems won’t be viable.

That E-fuels don’t work has even been noticed by the FDP(orsche) since yesterday. ;-)

One should definitely size the photovoltaic system according to own consumption. Scenario: -5 °C, overcast sky. Heat pump is chugging away, man or woman at the stove as well. The laundry needs to be washed and the electric horse also wants to get a bit. When just enough comes from the roof, the photovoltaic system is not oversized.