Households throughout Cape Town will soon have technicians knocking on their doors to install load control relays, which will allow the municipality to switch off hot water geysers remotely.

Also known as ripple relays, the energy-saving devices will be installed at no cost as part of Eskom's drive to save power. The project is being run jointly by Eskom and the city.

So far, over 2 000 have been installed in Kraaifontein, Kuilsrivier, Eversdal and parts of Tableview.

While the programme is being run throughout South Africa, the people of Cape Town have shown the most resistance to having the devices installed in their homes.

On Tuesday, Pearson Sibanda, who is responsible for implementing the project in Cape Town, said they had come across hundreds of households in Cape Town who had refused to have the devices installed. He said the refusals seemed to be more common in the wealthier suburbs.

"They say they don't care, they have enough money to pay their electricity bills so they don't care about saving electricity," Sibanda said.

Eskom's energy services manager, Tsholo Matlala, has said that current projections indicate that by 2010 South Africans' demand for electricity will exceed supply at peak hour periods.

He said the Western Cape, in particular, faced problems meeting the demand for electricity.

Residential households consumed 17,5 percent of electricity generated, and household peak period demand was over 30 percent.

Because most of this household energy was consumed by geysers, Eskom was targeting geysers in managing electricity demand.

The programme of installing ripple relays on geysers was designed to "smooth out" the peak demand period.

Sibanda said once the ripple relay had been installed in a house, it would mean that the geyser could be switched on or off by the municipal energy centre. The system would switch the geyser off only during peak periods.

He said even when the power had been switched off, water stored in geysers would be hot enough for normal use. While there would not be direct savings to the customer, the municipality would save money by shifting the load from peak times - when Eskom charged higher rates - to off-peak times. This would also mean that the generation, transmission and distribution systems would not have to be expanded in the short term, helping to keep tariffs down.