Solar geyser quotes from local installers

Why heat water with the sun

Heating water is one of the largest electricity costs in most South African homes, because a geyser element draws a lot of power for hours every day. A solar water heater does most of that work with free energy, and the electric element only comes on when the sun can't keep up.

There are two ways in: a complete new system with its own tank, or a conversion that adds solar collectors and a small pump to the geyser you already have. Conversions cost less and suit geysers in good condition; a new system makes sense when the old geyser is near the end of its life.

Flat plate or evacuated tube?

Direct or indirect: frost matters

In a direct system, the household water itself flows through the collectors. It's simpler and slightly more efficient, but if water freezes in the collectors on a winter night, it can burst them, and in hard-water areas scale builds up inside.

In an indirect system, a sealed loop of heat-transfer fluid with antifreeze runs through the collectors and passes its heat to your water through a heat exchanger. It costs more, but it doesn't freeze or scale up. In frost-prone areas, such as much of the Highveld and the interior, an indirect system or proper frost protection is essential. Ask every installer how their system handles frost where you live.

Placement and backup

Collectors work best facing north at a suitable tilt, without shade from trees or neighbouring buildings for most of the day. The installer should check your roof's orientation and structure before quoting.

Every solar geyser keeps an electric element as backup for cloudy days. Fitting a geyser timer or smart controller so the element only runs when it's needed, such as late in the afternoon after the sun has done its work, is where much of the saving comes from.