Photovoltaic system: How many kWp are enough for a house?

to come back to the topic once again. I specifically installed a 1000l layered buffer tank in my house, which I would like to heat up during the day and then use for heating at night. But as I said, I currently lack experience with it, since I have many, many other ongoing projects...

The initial question is like "How much horsepower is enough for a vehicle".

If you consider the system as a financial product, you can currently still build on a large scale - with the limitation that the remuneration conditions change at 10kWp and there is a small "jump" in the calculation.

If you consider the system as a sustainability investment, you can size it so that it produces more in total than you consume.

If you consider the system as a self-sufficiency instrument, you will calculate differently again to determine "sufficient".

Have you ever calculated whether it can actually be worthwhile? Self-consumption is by no means free. In addition, you accept efficiency killers like extreme hot water storage and buffer tanks.

yes, if there is a buffer storage involved, then I don't know if it's not more of a loss calculation after all.

I would have increased the supply temperature and the floor heating by 1 to 2 °C and used the screed as a buffer. But with an additional buffer, even more efficiency is lost and the acquisition costs have to be recovered first... whether that's still worth it?

We have 7.5 kWp on the roof, plus a 7.7 kW storage. The heat pump heats the house during the day when there is excess electricity (screed as a buffer) and raises the hot water temperature. The storage lasts until the next morning. Everyone has a different opinion: do the full amount; do up to 9.9 kWp; do without storage; etc...

We have 7.5 kWp on the roof, plus a 7.7 kW storage. The heat pump heats the house during the day when there is surplus electricity (screed as a buffer) and raises the hot water temperature. The storage lasts until the next morning. Everyone has a different opinion: go full; make up to 9.9 kWp; do it without storage; etc...

We have an offer for 19 modules with 360W. More probably wouldn't fit