I know from my travels discussing voltage optimisation, some folk are yet to be convinced of the benefits of voltage optimisation, so in this blog I will give some real life examples of how it works within a domestic environment and dispel some of the rumours.

One of the assumptions that is often made is that ‘voltage optimisation would make no difference to energy costs for the domestic customer as you are charged by KWA and not by voltage, although there may though be carbon efficiency reductions.’ The VO4HOME unit makes a difference for both energy costs and carbon efficiency reductions. The VO4HOME unit optimises the incoming voltage to a constant 220V giving householders (or indeed small businesses) immediate energy savings. Typical savings with VO4HOME are around £90 per year. Yes, householders are charged by the KVA but excessive voltage results in greater KVA / Power demand, hence increasing your electricity bill. So aside from reducing costs and carbon, the unit reduces wear on household appliances caused by electrical over-supply and power surges. Another common assumption is that… ‘Devices that require a certain amount of electrical power, like an oven - it takes X kWh to heat up a particular oven and keep it hot for 90 minutes. Voltage optimisation will do nothing for this sort of device as it will just take longer to get the oven hot by powering it at a lower voltage and the thermostat will cut the element in for slightly longer to keep it hot therefore no savings are achieved.’ A conventional oven is designed to work perfectly well on 220V as much as 240/250. It does not take the same amount of kWh to heat an oven to a specific temperature and keep it hot for 90 mins and there are benefits in voltage optimisation in these appliances as less energy is wasted in the cooling/re-heating phases due to thermostatic control. Typically 7% savings can be observed, not to mention that all modern household appliances are energy rated which is rated on the appliance been run at 220V (the optimum voltage for use in the EU). However, it does take exactly the same amount of energy to boil a cup of water whether you use 220v or 250v. Also there are significant benefits from the appliance been run at a lower voltage than 240V in fact the following, originally published by the IEE underpins this technology: “A 230V linear appliance used on a 240V supply will take 4.3% more current and will consume almost 9% more energy.” (UK Electrician’s Guide, 16th Edition BS7671.) “A 230V bulb used at 240V will achieve only 55% of its rated life.” (UK, IEE Electricians Guide) Fridges/Freezers benefit significantly from Voltage Optimisation as the motors run at their designed speed & heat, reducing excess heat produced by over voltage thus reducing the need to run in order to cool the appliance, typically inductive loads such as these types of motors can see a reduction in energy usage of up to 17%, the same goes for the motors on Air Con, (though not modern units using variable speed invertors) washing machines/tumble dryers and dish washers. Not to mention again the benefit in the extended life expectancy of the appliances due to them being used at the optimum voltage of 220V. VO4HOME have run test cases in conjunction with Npower & Hurley Palmer & Flatt where we achieved savings of 12% and currently whilst running a number of test studies to obtain our CERT value we have been showing savings of between 14-17%. I hope this gives you a clearer understanding of the benefits of voltage optimisation in the home and the savings which can be achieved. Mohamed Ghodawala - V4HOME Blog