All our systems have an electrical back-up element which would be affected by load-shedding. If it has been a good solar day it is unlikely that your element would need to switch on, however our pumped systems are installed with a 220V circulating pump and digital controller both of which require electricity to run and circulate your water.
If one has a back-up UPS this will eliminate any issues. Our thermo-siphon systems on the other hand naturally circulate hot water (natural convection) without the use of a pump and controller.
General rule of thumb:
If your roof is North facing or no more than 45° off North, we recommend the flat plate collector.
If your roof is more than 45° off North, we recommend the evacuated tube collector.
If your roof is flat, we recommend the flat plate collector.
There is a minimal amount of servicing required, cleaning the collector plus checking the pump and the various valves on the system. It may be necessary to replace the element and thermostat from time to time, depending on water quality.