I have cut my warm water costs by 80% with balcony solar panels. I have a warm water heating pump with 600 W electrical power. My little server turns it automatically on when the solar access power is greater than 540 W (measured by the smart meter). This generates usually enough warm water for our household.
Also the solar panels cover to idle power of the house of 50-100 W very easily during daytime. This pays off in a few years and it reduces my carbon footprint and that of my neighbors.
The hybrid (heat-pump & heat-elements, both) water heater I installed 2 years ago has already paid for itself in savings. This design literally pulls the heat out of your conditioned space, providing both cooling and dehumidification (I live in a humid temperate rainforest so win-win). <3% of my annual electric usage goes to my water heater (typically 10%+).
During the brief winter months I just set it to heating elements only, and it behaves like a traditional watertank heater (i.e. doesn't cool house in the winter, using only resistive heating).
I assume balcony solar panels provide you with a power socket. How do you connect all the appliances in house to that socket(s)? Isn't it a lot of cabling?
Well, the person you are replying to is in a thread about Germany, mentions balcony solar and said "my little server turns it automatically on" (which is how you would construct that sentence in German instead of "turns it on automatically"), so my wild guess would be Germany. ;)
Germany has a pretty consistent climate. Doesn't really matter where you live. Of course, that's an oversimplification, but if you're new to Germany and wonder "oh, what's the weather going to be here?", the answer pretty much is "similar to the rest of the country".
You could then look at a map of France and think, ah, similarly sized country, probably also has a consistent climate, but that's not true. Southern France is very different from Northern France. But Germany's climate is pretty uniform.
Yes, there is a difference, you are right. I don't have hard numbers at the moment (typing from the phone) but from looking it up quickly, the sun's intensity varies from about 950 kWh/m² to about 1.200 kWh/m² between north and south Germany. So, what OP described will generally work in any part of Germany.
