Hi,
We recently installed Solar and have what was originally an off-peak electrical hot water. We now have a diverter.
I think it is better to install a diverter e.g.
https://www.catchpower.com.au/ than to simple use a timer system in this case.
This makes much better use of the available electricity by spreading electrical consumption based on the available solar.
For example our HW takes about ~3kW. If the array is providing more than that no problem. If it is below 3kW then it is better to reduce the power consumption of the HW system and spread it across more hours of solar rather than exceed the solar power available and use power from the mains.
It also controls top-up to off peak time so you avoid heating during peak (as would a timer BUT you don't have to lose solar during peak cost times).
Anyway worth considering although in a strata title the real headache is costing the actual use of the HW.
However - a heat pump would be more efficient but I'm unsure how it works out in detail as I believe they can only be operated at full load?
Anyway, something to consider.
bye