Voltage Optimisation - Background

Background

Voltage optimisation is an electrical energy saving technique which is mainly installed in series with the mains electricity supply to provide a reduced supply voltage for the site's equipment. Typically, voltage optimisation can improve power quality by balancing phase voltages and filtering harmonics and transients from the supply, although not always. Voltage optimisers are essentially transformers used to deliver power at a reduced voltage from the raw mains supply.

The term voltage optimisation is frequently misused, as the term implies some form of selective voltage reduction, which will improve the energy consumption within a building, whereas generally these units consists of a transformer within a box, offering no selectively and dropping voltage on all supplies, whether this would offer a commercial benefit or not. Some VO units have been installed on high frequency lighting circuits, offering little or no commercial benefit, therefore one must be careful when the term is used.

Most VO units are installed in commercial premises, in between the raw mains transformer and main low voltage distribution board. However, this provides for no selectivity and in electrical engineering terms is considered a poor solution. A full study should be undertaken by the facilities manager and VO company, to select which supplies could benefit the owner by reducing the voltage and which supplies would give no commercial benefit. This way the owner only purchases a VO of the correct size and not one that's for all supplies. Installing a VO unit to 'optimise' all supplies would give a longer return on investment, a higher capital outlay and makes no commercial sense.