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Cut the volts for shock savings

Most electrical appliances don't need the high voltage supplied in your mains, writes David Derbyshire

It's quick to install, cuts your fuel bills by 10% and could save enough electricity to take an entire coal-fired power station off the National Grid.

"Voltage optimisation" may not roll off the tongue, but a growing number of energy experts believe it could become a key weapon in Britain's fight to slash carbon emissions.

The technology is so successful it has already been installed by the Department of Energy and Climate Change (DECC) at its Whitehall offices as well as at the headquarters of the power regulator Ofgem and at 10 Downing Street, where the system cut electricity bills instantly by 10%.

Despite the potential, however, manufacturers say the government is dragging its feet over the technology while promoting less efficient energysaving schemes.

Large scale voltage optimisation has been used by factories and office blocks for decades, but it has become available to domestic customers only in the past few years. The technology works by reducing the voltage of mains electricity entering a home or business.

By law, electricity companies can supply power between 207 volts and 253 volts. All electrical appliances in the home — from fridges and hairdryers to central heating pumps and televisions — are designed to work with a voltage in that range.

The flexibility means that if the voltage suddenly drops — say because a power station breaks down or demand rises unexpectedly — homes and offices keep running and the lights stay on.

In practice, electricity companies keep the voltage at the higher end of the scale, with an average 245 volts.

Yet many Household appliances run most efficiently at the lower end, between 210 and 220 volts. Above 220 volts, appliances waste electricity. Motors give off more heat and computers and televisions burn out more quickly.

Voltage optimisation reduces the voltage coming from your mains to a more efficient level. Some optimisation units are transformers that step down the voltage by a fixed amount — such as 20 volts or 30 volts. Others are more sophisticated and cancel out any excess voltage above 220 volts.

Whatever system is used, the effects can be dramatic. Vphase, a Manchester firm that has developed a voltage optimisation unit with the backing of Liverpool university's engineering department, said it can reduce household electricity bills by 10% to 12% as well as extend the life of appliances.

The Vphase device, which is a bit smaller than a shoe box and must be installed by an electrician on to a home's fuse box, costs about 300 supplied and fitted. A typical family home can recover the cost within four or five years.

The sort of savings you get with voltage optimisation depend on the nature of the appliances being used. It can reduce the electricity consumption of fridges and freezers by 17%, and cut the power needed to run lights by 15%. Televisions, DVDs and computers use about 5% less electricity.

The only devices voltage optimisation doesn't help are those that convert electricity into heat — appliances such as kettles, electric cookers and electric fires. In a house equipped with voltage optimisation a kettle typically takes 15 seconds longer to boil.

Rick Smith, chief executive of Vphase, said that, despite the reductions the technology delivers, it is struggling to gain government support.

It is excluded, for example, from the government's energy efficiency rating system for homes, called the Standard Assessment Procedure (SAP).

Industry chiefs met last week with regulators to get voltage optimisation added to the list.

The industry believes that, if voltage optimisation is included in the SAP scheme, builders will have an incentive to add it to new homes. It is also more likely to be covered by the government's upcoming Green Deal — an initiative to help householders make their homes more energy efficient.

"It's a proven technology," said Smith. "DECC, Ofgem, the Tower of London and Tesco all use it, yet it is being made difficult for homeowners to access it. If we are included in the SAP list, most new homes will look to fit voltage optimisation, which would result in more energy efficient homes.

"We also believe Vat should be reduced to 5% on voltage optimisation units — just like it is for other energy efficiency measures such as ground source heat pumps. The Treasury has allowed the reduction for things like heat pumps even though the technology and savings aren't as good."

Last week Baroness Worthington, who helped draft the previous government's climate change act, called for the energy department to help promote voltage optimisation.

"This is a really innovative solution that is cost-effective, yet it is struggling to get recognition from the government," she said. "And why can you get Vat reduced for heat pumps, but not this? If it was widely distributed, the amount of energy saved would be enough to take a mid-sized coal-fired power station off the National Grid."

The department responded: "DECC will meet companies and experts on voltage optimisation in the coming weeks to get a shared understanding of the benefits it can bring and what steps would be needed if it were to be included in the Green Deal framework."


Copyright David Derbyshire 2012