It’s likely that voltage optimisation will only be of interest to you if you have particularly high electricity bills. The percentage savings are likely to be modest, so it really only makes financial sense when your bills are high.

How voltage optimisation works

In the UK the mains voltage supply usually varies between around 230V and 250V, however most electrical equipment is designed to operate efficiently at lower voltages (typically around 220V) found elsewhere in Europe.

Voltage optimisation (VO) reduces the voltage of your home’s incoming supply to around 220V. Electrical appliances will still function well, but less energy will be wasted as heat, especially in devices with motors such as fridges and washing machines, and in devices which have transformers. 

Another advantage is that some electrical equipment will last longer as there is less risk of it overheating when run at lower voltages.

Not all electrical appliances offer opportunities for cutting energy use.  Modern motors are starting to incorporate electronics which already do the job of a VO device so the potential for savings is reducing with new kitchen appliances.  Appliances using electrical resistance (e.g. incandescent lighting, heaters and ovens) will operate at a slightly lower power output and if thermostatically controlled, will compensate by running for a longer period of time.

Potential costs and savings

VO devices should be fairly straightforward for an electrician to fit adjacent to your existing distribution board.

For an installation to offer worthwhile savings, your existing supply voltage should exceed 240V.  At present domestic VO devices are available from £350 upwards, with an estimated fitting cost of £200.  Electricity savings of around 5-6% have been reported in trials of the technology, but the results were very dependent on the mix of appliances in any given property.




Home Energy – Voltage Optimisation (L1)                                                                                 


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