Thank you for the many responses.
Something must be wrong there. A difference of €1000 is 7700 kWh from the grid alone. That is 30,000 kWh of heat with the current heat pump. Before I start worrying about the meters, I would have my plumber come.
In general, nowadays it usually does not make sense to install a second meter in new buildings (because of the second basic fee). As the share of renewable energy increases, the price difference between heat-pump electricity and normal electricity will also decrease, so it won’t make sense for anyone else either.
You also have to consider that I would have to install a different heating system if it is not allowed to run for four hours of the day. It would then have to be designed about one-sixth stronger. If there is no more suitable option anyway, okay. But if I have to take the next larger model for that, I better forget about the second meter.
Photovoltaics were, of course, not included in that. Because of that, it is significantly less.
According to the preliminary energy calculations, we are at just under 35 kWh per sqm per year. That is about 9000-10000 kWh consumption for the heat pump with 270 sqm usable area or 235 sqm living area (no basement) and the open design. I’m curious what the actual consumption measurements will show.