Some basic isolation will definitely help, as does a behaviour change from showering in the evenings as opposed to the mornings.
IMHO expecting the heat to last several days is unrealistic, but you should have a tank sufficiently sized for allowing all your family members to shower and then some, as the heat doesn’t get produced on demand. 300-500 liters is normally more than sufficient.
For my system I get some heat out of it even on cloudy days and then use the heat-pump to top it off to a nice shower temperature. But again this requires to wait for the evening to shower.
Also realistically speaking, in climates with strong freezing temperatures the risk of the system freezing and breaking is quite high and you probably really do not get much out of it in the winter, so maybe it’s not the best solution for such climates.
Some basic isolation will definitely help, as does a behaviour change from showering in the evenings as opposed to the mornings.
IMHO expecting the heat to last several days is unrealistic, but you should have a tank sufficiently sized for allowing all your family members to shower and then some, as the heat doesn’t get produced on demand. 300-500 liters is normally more than sufficient.
For my system I get some heat out of it even on cloudy days and then use the heat-pump to top it off to a nice shower temperature. But again this requires to wait for the evening to shower.
Also realistically speaking, in climates with strong freezing temperatures the risk of the system freezing and breaking is quite high and you probably really do not get much out of it in the winter, so maybe it’s not the best solution for such climates.