Alternative geyser options. Image by Nicola/Pexels

What is cheaper: Gas, solar or heat pump geysers?

Geysers add a lot to electricity bills, but cheaper options are available to replace your conventional geyser. Here is a closer look at them.


Alternative geyser options. Image by Nicola/Pexels

Electricity tariffs keep increasing and winter is here, so many of us want to have a relaxing bath or a quick shower to warm up. South African households can save money on water heating by replacing their conventional electric geysers with a gas, solar, or integrated heat pump geyser. The question is: what is cheaper? Here is a comparative look at the available options.

How much electricity does a conventional geyser use?

Conventional electric geysers can make up between 40% and 60% of a household’s monthly electricity usage, according to MyBroadband. Increasing the water temperature requires heating a conductive element, similar to the one in a kettle but significantly larger. These elements’ power consumption can vary between 1kW and 3.5kW. A household of four that needs to shower or bath every day will require an electric geyser to heat their water tank multiple times during the day.

Following is a summary of three types of geysers that can reduce your expenditure.

Solar water geysers

The main components of solar geysers are basically a water storage tank and a solar collector. There are two types of solar geysers: direct and indirect. The first heats water directly and the second uses a heating liquid which mixes water and glycol.

Gas option

Gas geysers heat a radiator with a burning flame in an enclosure. Water is pumped through this radiator and heated rapidly for consumption. This system does not need a large storage tank, but you need space for the bottle that holds its gas.

Integrated heat pump geysers

Important to point out, is that integrated heat pump geysers require electricity as its primary heating source. However, it consumes around 80% less electricity than conventional geysers by using reverse refrigeration.

“A heat pump is a bit like a reverse-action air-conditioner. Where the air-conditioner transfers heat from the air inside a room to the atmosphere outside, a heat pump transfers heat from the air around it to the water in its geyser.”

Mike Alton, co-founder of HydraTherm

So, what is cheaper?

In light of the brief descriptions of the three types of geysers that could save you money, let’s see how it could be better on your wallet.

Altogether, the average monthly running cost for a household of four people for a:

  • gas geyser is R706
  • 200 litre solar geyser is R351
  • 200 litre integrated heat pump geyser is R234

If 40% of the average South African household’s 900kWh monthly electricity consumption goes towards heating geysers, the element will consume roughly 360kWh per month. On a Block 2 tariff in the City of Tshwane, that works out to about R1 170 per month. So, it seems either of the three alternative options for geysers will be cheaper on a monthly basis. Installation costs, however, must also be considered.

Pros and cons

All the alternative options for geysers have their benefits and disadvantages.

Gas geyserRequires fine-tuning for different seasons
Sensitive to pressure variations
Requires safe storage and line for gas bottle
Gas prices influence cost-effectiveness
Fast heating
Not reliant on electricity
More eco-friendly 
Lifespan is about 12 years
No risk of geyser bursting
Solar geyserRequires an upfront investment that can be costly
Needs routine maintenance on the valves
Takes up roof space
Free heating when the sun shines
Not reliant on electricity
Integrated heat pump geyserRequires electricity
Must often be installed outside
Fast heating
Highly efficient energy consumption