The most power hungry device in the home is an electric geyser using an electrical resistance element. The most efficient energy saving technology for replacing electrical heating in a domestic home is a solar water heater (see our section on the basics of solar water heating).
Heat pumps are an alternative to solar and electrical resistance elements, but have generally been found not to deliver the promised electrical savings in the home, due to a combination of reasons. Consequently all energy incentives for domestic heat pumps were suspended. However heat pumps in a commercial environment where large volumes of water are being heated, for example hotels, can be extremely attractive saving up to 70% approx. of the energy consumed through electrical resistance elements.
Low-flow shower heads where the amount of hot water used reduces to approximately 10 litres per minute, instead of 15-30 litres per minute, indirectly saves energy by reducing the amount of hot water consumed, and therefore enables the hot water to go further. They do not save the electricity directly.
Staying with electric water heating through a resistance element is of course an expensive option if a consumer believes they cannot afford to go solar. Consumers should consider some of the solar rental models, which enable the consumer to be better off immediately over staying with an electric geyser, without the large capital expenditure of buying a solar system.
If the electric resistance geyser is to remain consumers should for energy efficiency set the thermostat to a maximum of 55 ºC, check that the element is not corroded or heavily coated with lime scale, (this can use up to 30% more power for heating the water), make sure the sacrificial anode is not exhausted, and consider a geyser blanket. To save energy smaller baths or shorter showers will save electricity.
If a home has a mains gas connection, gas boilers are an attractive option to consider being considerably cheaper to run than electric geysers.
Other technologies that claim to save electricity, for example induction geysers need to be approached with considerable scepticism. Frequently electrical savings claims are found to be spurious and misleading. Before buying, empirical evidence of savings should be provided.