What Is Voltage Optimisation And Can It Reduce Energy Consumption?

The truth about voltage optimisation is that it can save you money. Voltage optimisation is a reduction of the incoming mains power supply voltage down to a lower but safe level to power equipment running on our site. However, savings are very much dependent upon existing pre-optimisation voltage levels, the loads on a site, any other energy efficiency improvements being made and off course the future of cost of electricity.

Taking these in order, the first thing to assess is the present mains voltage level prior to installation of a voltage optimiser. As users are charged in kilo-Watt-hours (kWh) by electricity supply companies and the kW used is related to the mains supply voltage, the higher the voltage the more kWhs will be used. Often a voltage optimisation company will gladly measure your mains supply voltage but this really needs to be recorded over a long period of time with backup date from the local District Network Operator (DNO) where possible. Mains voltages rise and fall due to peak demands and time of year. They are rarely static over a year.

The mix of loads on site can also affect savings. Certain loads are unaffected by a reduction in mains voltage. Thermostatically controlled systems show fewer saving where as motors, resistive heating, lighting and motors can show savings up to 25% or more. Computer type loads using Switch Mode Power Supplies (SMPS) show minor savings of less than 5%. Care has to be taken when lowering the mains supply voltage through optimisation with the length of supply cables from the building incomer. Voltage drops over long cable runs due to internal cable resistance and if set to low at the voltage optimiser, the level reaching the load could affect its operation.

On some sites voltage optimisation makes sense and the financial models show a short payback period and good Return On Investment (ROI). However, this may only be true when no other efficiency measures are put in place. Retrofitting lighting to LED T5 lighting will save energy consumption on site but would reduce the overall energy savings generated by the voltage optimiser. Voltage optimiser projects are financial model sales. They are dependent upon the factors discussed above and also the future cost of energy. Rising electricity costs can reduce potential voltage optimisation benefits and increase payback periods.

In summary, voltage optimisation may not be right for every site and like any energy efficiency project, it should be viewed holistically as part of a wider organisation project, taking into account future costs of energy and other energy efficiency measures being taken. For more information see the EcoPowerSupplies voltage optimisers range.