You could, but the idea is to only heat water when necessary (there isn’t enough hot water and you need to take a shower), keeping it hot all the time is wasteful.
Running a thermostat 15-30 minutes before the hot water is needed would only consume electricity if the water is not already hot. You probably want a well insulated accumulator tank with one of these systems to not lose the energy produced as well.
You could, but the idea is to only heat water when necessary (there isn’t enough hot water and you need to take a shower), keeping it hot all the time is wasteful.
Running a thermostat 15-30 minutes before the hot water is needed would only consume electricity if the water is not already hot. You probably want a well insulated accumulator tank with one of these systems to not lose the energy produced as well.