The heat pump calculator on this site sizes one quote against a plain electric geyser. A homeowner holding that quote is usually holding two more: a solar geyser and a gas geyser. Those are different machines, so they did not belong as extra columns on the heat pump page, and they do not belong inside the solar savings calculator (that one is PV for the whole house).
The ranking reverses by climate. That is the finding that made a sibling page worth building. Highveld and Karoo winters are harsh for a heat pump and strong for evacuated tubes. Cape Town is kinder to the compressor and weaker for solar thermal, because the wet winter is when you want the hot water. On matched capital (heat pump and solar ETC both R30,000, working geyser, 4 people, 150 litre tank) Cape Town’s heat pump comes out ahead and the Highveld solar geyser does.
Gas is the cheap quote and the expensive kilogram. A Paloma-class 16 litre-per-minute unit installed sits around R20,500 in 2026. At R40 per kilogram, useful heat costs about R3.46 per kWh, versus about R1.22 for a national-average heat pump on a R3.20 tariff. It wins the first year and usually loses the tenth. It is also the only one that still showers during an outage, which the tool reports as a bonus strip, not as a rand in the payback.
Starting prices are named 2026 quotes, not blog ranges. A 200 litre Kwikot tank with 20 evacuated tubes, fully installed by Juspropa, is R29,500. The Paloma 16 L Eco Lite from a Paloma Preferred Installer is R10,850 for the unit and from R20,500 installed. Solar fraction is locked to Stellenbosch field data (Cape flat plate 70.4 percent annual) plus an inland-versus-coastal modelled gap, not a flat national 70 percent that would erase the reversal. Overwrite every figure with the quote in your hand.
Try it here: Compare Heat Pump, Solar & Gas Geysers SA
Estimates to sanity check three quotes on the same household, not a substitute for any of them. I would be interested to hear what installers in your area are actually quoting in 2026 for a 200 litre evacuated-tube solar geyser and a 16 litre-per-minute quality gas unit, especially once CoC, cage and cylinder deposit are in the number.