Consultation for photovoltaic system

Ah, you probably meant the size of the storage. Misread. Sorry.

I still want to come back to the size of the photovoltaics: If you want to charge a medium-sized electric car in winter (and yes, everyone here will want that in at most 10 years), it takes a full two days with bad weather and a 50 kWp system. Whether there is a storage unit in the basement or not doesn't matter.

So if you're thinking about photovoltaics, you shouldn't waste time with 10 kWp gimmicks, but rather fill the roofs completely.

Ah, you meant storage capacity. Misread. Sorry.

No. The heating requires 12 kWh on a winter day + 5-8 kWh for household. I want to see the estimate (cost) of the system (modules/appropriate storage/installation/other...maintenance...) for my self-sufficient house. Semi-detached house with approximately 100 sqm roof area (50 sqm at 15 degrees, 50 sqm at 25 degrees south)

No. The heating requires 12 kWh on a winter day + 5-8 kWh household.

I want to see the range (costs) of the system (modules/appropriate storage/installation/other…maintenance…) for my self-sufficient house.

Semi-detached house with approx. 100 sqm of roof area (50 sqm 15 degrees, 50 sqm 25 degrees south)

100 sqm is not enough for a self-sufficient house. Have you looked exactly how much photovoltaic you can install?

Roughly estimated, you end up at 15-20 kWp. That is of course not bad, but still quite far from self-sufficient.

So here the probability is still high that the storage will not be full in winter!

I want to see the costs of the system (modules/appropriate storage/installation/others…maintenance…) for my self-sufficient house.

Quite demanding. But alright: The rule of thumb is 1000,-€ per installed kWp as well as installed kWh storage. Currently, due to material shortages, about 10-20% more expensive. There is no suitable storage because that is nonsense. Installation is included. Others depend on your house, so it is best to discuss with the solar installer. Maintenance, given your low roof pitch, would possibly be cleaning every few years.

This is not a sprint. Then the battery just lasts longer.

Unfortunately, rather yes. It is a race against the failure of the battery electronics. It is not the storage cells that fail, as we experience in the automotive sector. Optimistic calculations therefore assume a battery lifespan of 15 years. And during that time, it should at least break even. Then, although it hasn't helped much besides environmental destruction, at least you haven't lost money. Well, and that only works if you actually fully charge and discharge it 200 times a year. The former requires a photovoltaic system that is at least three times larger (in kWp) than the battery (in kWh). The latter can basically only be done with senselessly high night consumption in the summer.

I already mentioned it: You have no idea HOW LITTLE power comes through when the weather is really bad! And unfortunately, that happens quite often (at least this summer...). I have 28 kWp on the roof, it is quarter past 9 and in my opinion, it is not autumn yet: