Construction costs are currently skyrocketing

What do you actually need a 300 liter hot water tank for.. That is pure energy waste. I have a 500 liter tank for 10 apartments! And that is more than enough. Normally, 120 L in a single-family house is totally sufficient, and less heating is needed accordingly.

Solar thermal energy is just as pointless. With the self-generated solar power, you can easily heat hot water. Without much technical effort. At least it works perfectly for me. From the end of February to the end of October, I have no costs for WW generation.

I believe this is a bit of modern luxury. As children, we were bathed once a week and otherwise used a washcloth, just as the adults did not shower daily. Today, many adults probably shower daily, sometimes even several times, and children bathe much more often. In this case, a large hot water tank is already sensible.

This heat pump+photovoltaic cladding here in the forum is really annoying sometimes.

Do "heat pump+photovoltaic" systems work without feeding electricity back into the utility grid? I read today from the "Hamburg nobility" ;-) that as of 01.01.24, utility providers will be allowed to throttle electricity supply for charging e-cars and heat pumps if their consumption is too high. Then heat pumps would only work with photovoltaics, or does that not help the end consumer in this situation either? (If the question is stupid, I apologize; I have not yet fully grasped the entire topic.)

But first, you need facilities that allow local throttling. Here, the basic supplier offers a cheaper tariff that can switch off your wallbox if needed via a small additional box with a mobile network connection. The savings come at the cost of the shutdown option. It’s unfortunate if you actually have to leave in the morning, but the car did not charge overnight.

Without such facilities, remote shutdown is impossible; it would only be possible for entire streets at once, but not for the individual heat pump user in the neighborhood, unless they explicitly have the option.

I think that's a bit of modern luxury. When we were children, we were bathed once a week and otherwise used a washcloth, just as adults did not shower daily. Today, many adults shower daily, sometimes even multiple times, and children bathe much more often. In that case, a large hot water storage tank is quite sensible.

Mr. Kretschmann, is that you?

But first you need facilities that enable local throttling. Here, the basic supplier offers a cheaper tariff that can shut off your wallbox on demand with a small additional box connected via mobile network. The savings are then bought with the shut-off option. It’s annoying when you actually need to leave in the morning, but the car didn’t charge overnight. Without such facilities, remote shut-off is impossible; it would only be possible street by street for everyone, but not for the one heat pump user in the neighborhood unless they explicitly have the option.

At night, electricity is usually cheapest because few consumers are active. A shut-off during this period is therefore highly unlikely. A common e-car also charges at home with 11 kW. Even if you had basically driven the vehicle empty, it only needs 5-7 hours of charging time for a full charge. An hourly interruption hardly jeopardizes this extreme scenario, and throttling even less so. This could be possible via smart meter.