Solar water heaters rely on the sun's energy to heat water. During the night time hours, the water in your solar water heater / hot water storage tank is not being actively heated, so if your geyser is emptied through the family showering and bathing, the water that re-fills the geyser will not be heated using the sun's energy – until the morning. Most solar water heaters are connected to electricity, as a back-up way of heating water when the sun's energy cannot be used to do this. So if you only use hot water in the evening, all the water that refills your geyser will be heated using electricity, and not the sun's energy. This means that you will not get the maximum electricity savings out of your solar water heater.
The best ways to maximise your electricity savings through your solar water heater are:
- To limit the use of hot water in your home or office
- To especially limit the use of hot water in the evenings or at night, and try to get bathing and showering, which uses the most hot water, done in the morning or during the day.
- To not connect your solar water heater / geyser to the electricity as a back-up, and live with cool water when the sun's energy cannot be used to re-heat water in your geyser (e.g. at night or very cloudy days).
- To regularly clean your solar collector panel, so that the maximum amount of sun's energy can always be absorbed
- To have your solar water heater regularly serviced