Voltage Optimisation - Improving Energy Efficiency
Share on LinkedIn15 Aug 2024
Voltage Optimisation is an energy saving technology which adjusts an incoming electricity supply’s voltage to that of the optimal level for running the equipment on site. Due to the optimised voltage supply, energy efficiency increases, and energy costs as well as carbon emissions decrease. This article will overview the reasons for implementing voltage optimisation technologies and how they work.
The Grid and Why to Use Voltage Optimisation
Historically, grid supplies in the UK were kept at a greater voltage than European grid supplies, that being 240V for residential and 415V for commercial and industrial buildings, in comparison to 220V and 380V respectively across Europe. This means that the UK grid provided greater levels of power to buildings than the European grid. In 1995, these levels were harmonised to approximately 230V for domestic properties and 400V for commercial and industrial buildings, with equipment currently made in the EU certified to run at around 230V. However, the UK national grid still runs at a slightly higher voltage due to infrastructure costs and maintaining sufficient voltage for properties later in the distribution line. Therefore, equipment in the UK may be running at a higher voltage than they are designed for, particularly those designed for a European market.
Supplying equipment with a higher voltage than required can impact the functioning of the equipment and reduce its lifespan. Unnecessary energy consumption in this way leads to wasted energy and money, and the production of carbon emissions. Voltage optimisation works to prevent these issues by providing a facility with only the necessary voltage for proper functioning of their equipment.
How Voltage Optimisation Works
A voltage optimiser, running in series with the electricity supply, lowers the incoming voltage supplied by the grid to the required voltage for use within the facility, returning any surplus voltage back to the grid. This both reduces the energy usage of the site and increases the regional energy supply. See below process;
There are two types of voltage optimisation systems, fixed and variable. A fixed voltage optimisation system reduces incoming voltage by a specific percentage. A variable voltage optimisation system reduces oncoming energy to a set voltage. There are also mixed systems which combine the two.
Different Impacts for Different Equipment
To receive the greatest benefits from voltage optimisation it is important to determine the proportion of voltage dependent and voltage independent electrical equipment in a facility.
Voltage dependent equipment has varying power usage based on the voltage it receives.
Voltage independent equipment does not change power usage under different voltages.
This means voltage optimisation is particularly relevant for voltage dependent equipment. Examples of voltage dependent equipment are incandescent lamps, inductive ballast fluorescent lamps and uncontrolled motor loads. Motor loads have been found to be significantly benefitted by voltage optimisation as many are operating at partial load, therefore having excessively high voltage and often having high levels of energy loss, which is reduced by optimisation.
Examples of voltage independent equipment are LED lamps, information and computer technology (ICT) and electric heating with effective temperature controls.
Benefits and Disadvantages to Consider
The main reason for installing a voltage optimiser is often to reduce energy consumption and related costs, however there are many other associated benefits. Reducing energy consumption would also reduce a company’s carbon footprint and provide good PR. Voltage optimisation, with equipment being run at the voltage for which they are designed, helps to extend the lifespan of equipment and improve energy efficiency. As an energy efficiency action, it has been proven to be effective with over 100 years of evidence.
There are some potential disadvantages, namely the cost, although this has a very fast payback possible within 1-2 years, and the risk of short-term disruption to the power supply when installing the optimiser – although this can be navigated in many scenarios. It is also important to make sure voltage optimisation does not reduce the voltage below levels required for optimal functioning of equipment, particularly if the building still uses some older UK equipment designed for 240V supplies, however this is always considered in implementation.
How NUS Can Help
If you are looking into implementing energy efficiency measures within your organisation, NUS’ specialist Energy Services and Sustainability (ESS) team can support you in finding and installing the best measures for your organisation, including voltage optimisation. For more information contact us online or find your local NUS office.
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