Voltage optimisers can efficiently regulate the incoming supply voltage and save money and energy while reducing your carbon footprint.
Energy consumption remains a pressing concern for households and businesses in the UK, with unit prices for electricity set to increase by 8.7% in April 2025. With little prospect of significant cuts to bills soon, you’ll want to explore other ways to reduce your electricity consumption.
One effective technology that has gained significant attention is voltage optimisers. These devices allow households and businesses to save energy and reduce emissions by ensuring the supply voltage remains optimum.
But what are voltage optimisers, and how do they work?
Quick Takeaways:
- Voltage optimisers ensure that electrical devices receive only the necessary voltage.
- There are fixed, dynamic, and bypass voltage optimisers.
- Voltage optimisers commonly achieve bill savings between 5% and 13% but can reach up to 25%.
- They help prevent appliances from deteriorating due to excessive voltage.
- Voltage optimisers can be used alongside solar panels to ensure a consistent voltage supply even when solar generation varies.
What Are Voltage Optimisers?
Voltage optimisers are energy-saving devices that regulate the voltage supplied to your home or business, ensuring that appliances receive only the necessary electricity.
Most of the electrical equipment manufactured in the UK is rated at 220V and operates efficiently at this level.
However, according to the Energy Networks Association (ENA), the electricity delivered to your premises is usually at 230 volts nominal for single-phase supplies, with a permitted range of variation from plus 10% to minus 6%.
If you’re being supplied with electricity at a higher voltage level than you need, you could have operational problems, waste energy and money, and be responsible for more emissions than necessary.
It forces your appliances to operate at a higher voltage, causing energy waste, higher bills, and increased wear on your electrical equipment.
Voltage optimisers reduce and stabilise incoming voltage, cutting unnecessary energy consumption and preventing fluctuations.
How Do Voltage Optimisers Work?
A voltage optimiser is installed between the main supply and a building’s electrical system to regulate incoming voltage before it reaches appliances. It ensures that electrical devices receive only the necessary voltage.
The device works in three key steps:
- Voltage Monitoring — It continuously measures the electricity supplied from the grid.
- Voltage Optimisation — If the incoming voltage is too high, the optimiser lowers it to the desired range. It can also slightly boost it when it falls below the required level.
- Stable Output Delivery — The optimised voltage is sent to appliances, ensuring consistent performance without unnecessary energy consumption.
What are the Types of Voltage Optimisers?
Fixed Voltage Optimisers
Fixed voltage optimisers reduce the incoming voltage by a pre-set percentage. They’re designed for properties where the supply voltage is consistently higher than needed but does not fluctuate significantly.
Fixed voltage optimisers are a simple, effective, and lower-cost option that can provide steady energy savings. However, they’re less effective if voltage fluctuates frequently and cannot adjust dynamically to changing supply levels.
Dynamic Voltage Optimisers
Dynamic voltage optimisers continuously monitor and adjust the voltage in real time, ensuring it remains optimal even when supply fluctuations occur.
They’re more adaptable and efficient than fixed voltage optimisers and can help protect sensitive electrical equipment from voltage surges.
They also provide consistent savings by adjusting voltage levels dynamically. However, they cost more than fixed-voltage optimisers and require a more complex installation process.
Bypass Voltage Optimisers
These optimisers function like fixed or dynamic voltage optimisers but include a bypass switch, allowing you to turn off the optimiser if necessary. This feature is useful if you’re looking for flexibility in your energy management.
Bypass voltage optimisers are suitable for situations where you don’t always need voltage optimisation.
They can ensure uninterrupted power supply during maintenance or testing and are easily integrated with fixed and dynamic voltage regulation.
However, they’re more expensive than standard fixed optimisers and require regular monitoring to ensure bypass mode isn’t left on unnecessarily.
What Are the Benefits of Voltage Optimisers?
Reduced Electricity Bills
Voltage optimisers help reduce electricity bills by ensuring that appliances receive only the necessary power.
By regulating the supply, a voltage optimiser lowers the energy drawn from the grid. Appliances still function efficiently but without the additional waste, leading to noticeable savings over time.
The Energy Managers Association notes that voltage optimisers commonly achieve savings between 5% and 13% but can reach up to 25% in particular circumstances, like in buildings with high voltage and old light fittings.
Lower Carbon Emissions
Voltage optimisers help reduce carbon emissions by lowering energy consumption and ensuring your appliances operate efficiently.
When electrical appliances receive more voltage than they need, the excess energy is wasted as heat. This leads to unnecessary demand from power stations, many of which still rely on fossil fuels.
By optimising voltage, less electricity is used, directly reducing carbon emissions. Lower energy demand means power stations burn fewer fossil fuels, helping to reduce the environmental impact of electricity generation.
Even a slight reduction in energy use can make a big difference when scaled across multiple properties. A study by Ofgem shows that a 9.1% reduction in electricity consumption is equivalent to an annual carbon dioxide emissions saving of 165,700kg.
Extended Equipment Lifespan
Appliances that run on unnecessarily high voltage generate excess heat, which leads to wear and tear over time.
The IET Wiring Regulations BS 7671, the standard for electrical installation work in the UK, notes that when appliances with design voltages of 230V are required to work at 240V or above, their work life is shortened by 46%.
Voltage optimisers help prevent such wear and tear from excessive voltage and make devices more reliable and efficient.
Operating equipment close to its fundamental design value may maintain the life expectancy in line with the manufacturer’s expectations, leading to lower maintenance and replacement costs and long-term savings.
Enhanced Return on Investment (ROI)
Voltage optimisers yield quick and substantial returns on investment by reducing energy costs, extending equipment lifespan, and lowering maintenance expenses.
By cutting unnecessary electricity consumption, businesses and homeowners can achieve long-term financial savings that outweigh the initial installation cost.
For commercial properties with high energy demands, this translates to thousands of pounds in savings annually.
Where Are Voltage Optimisers Used?
Homes and Residential Properties
While voltage optimisers are more commonly used in commercial settings, some homeowners install them to reduce energy bills and extend the lifespan of appliances. They are most beneficial in homes where:
- The incoming voltage is consistently high (above 240V)
- There are older appliances that are sensitive to voltage fluctuations
- High-energy use appliances like electric showers, washing machines, and air conditioning units are frequently used
However, homes with modern, energy-efficient appliances may see fewer benefits, as many newer devices are designed to handle a range of voltages efficiently.
Businesses and Commercial Properties
Commercial buildings often consume large amounts of electricity, making voltage optimisation a cost-effective solution. Some of the most common commercial applications include:
Offices and Corporate Buildings
- Computers, printers, and office equipment run more efficiently with a stable power supply.
- Reducing excess voltage can reduce energy costs for lighting, air conditioning, and heating systems.
Retail Stores and Supermarkets
- Large refrigeration units and freezers require a stable voltage to operate efficiently.
- Optimisers can reduce power wastage from lighting, air conditioning, and security systems.
Hotels and Hospitality
- Hotels are prime candidates for voltage optimization because their heating, ventilation, and air conditioning (HVAC) systems use a lot of energy.
- A stable and efficient power supply benefits kitchens, laundry services, and entertainment systems.
Industrial and Manufacturing Facilities
Factories and warehouses have some of the highest electricity consumption levels, often using heavy machinery that operates continuously. Voltage optimisers help:
- Prevent overheating and breakdowns in motors and industrial equipment.
- Reduce electricity costs for conveyor belts, welding machines, and automated systems.
- Extend the lifespan of sensitive electrical components.
Healthcare Facilities and Hospitals
Hospitals rely on a stable power supply for life-saving equipment, making voltage optimisation a valuable addition. Benefits include:
- Protecting MRI scanners, X-ray machines, and other medical equipment from voltage fluctuations.
- Reducing electricity costs for lighting, HVAC, and general electrical systems.
Data Centres and IT Facilities
Data centres consume vast amounts of electricity due to continuous server operation and cooling systems. Voltage optimisers help by:
- Reducing energy waste in server rooms and cooling systems.
- Protecting sensitive IT equipment from power surges and fluctuations.
Can You Use Voltage Optimisers with Solar Panels?
You can use voltage optimisers alongside solar panels, and in many cases, they can enhance the efficiency of your renewable energy system.
Solar power output can fluctuate based on weather conditions. Integrating a voltage optimiser can help stabilise voltage levels and ensure appliances receive a consistent electricity supply.
How do Voltage Optimisers work with Solar Panels?
Solar panels generate electricity used immediately, stored in a battery, or exported to the grid.
However, fluctuations can occur since the power output is affected by weather and other conditions. Such volatility can create challenges for grid stability, as sudden drops or spikes in generation affect voltage levels.
Voltage optimisers help smooth these fluctuations by ensuring a consistent voltage supply, even when solar generation varies.
They achieve this by adjusting the incoming grid voltage and regulating the output from solar panels, reducing the risk of voltage spikes or dips.
This stabilisation supports the seamless integration of renewable energy into the grid while protecting appliances from sudden changes in power supply.
What are the Benefits of Using a Voltage Optimiser with Solar Panels
- Improved Grid Stability — Voltage optimisers help balance fluctuations in solar power generation by keeping voltage levels within an optimal range. This reduces stress on the grid and prevents overvoltage issues, especially in areas with high solar penetration.
- Increased Energy Efficiency — Solar panels and other renewable sources operate more efficiently when voltage is regulated. A voltage optimiser ensures energy is used effectively rather than wasted as excess heat, improving the system’s overall performance.
- Longer Equipment Lifespan — High or unstable voltage can wear out electrical components in solar inverters and household appliances. A voltage optimiser helps protect equipment, reducing maintenance costs and extending lifespan.
- Better Export Control — Some solar systems struggle with overvoltage when exporting excess energy to the grid, causing inverters to trip and reducing export efficiency. A voltage optimiser helps regulate voltage, preventing disruptions and allowing more solar energy into the grid.
- Lower Electricity Bills — If your solar panels don’t generate enough electricity to cover your needs, a voltage optimiser can still reduce energy consumption from the grid by ensuring you only use the required voltage.
Final Thoughts
If your home or business receives higher-than-normal voltage, a voltage optimiser can help regulate it and offer bill savings and a longer lifespan for your appliances and equipment.
Using less electricity directly lowers carbon emissions and helps to reduce the environmental impact of electricity generation.
You can also achieve higher sustainability by using voltage optimisers with solar panels to enhance the efficiency of your renewable energy system.
Frequently Asked Questions on Voltage Optimisers
1. Can I Install A Voltage Optimiser Myself?
It’s strongly recommended that you only use a qualified and experienced electrician to install the voltage optimiser.
Although the process is relatively straightforward, it requires planning and coordination, and any work involving electricity can be dangerous.
2. How Long Does it Take to Install A Voltage Optimiser?
Depending on the system size, installation can take 1-2 hours for homes and a few days for businesses. However, each site will have specific requirements, and each installation should be considered differently.
3. Will Voltage Offer Savings on All Equipment?
No. Savings will vary from one piece of equipment or appliance to another. How much you can save will depend on the incoming voltage, duty cycle, and the electrical appliance you’re optimising. The installer will conduct an initial site survey and quote you for potential savings.
Sources and References
- https://commonslibrary.parliament.uk/research-briefings/cbp-9714/#:~:text=Unit%20prices%20for%20gas%20will,than%20in%20winter%202021%2F22.
- https://www.energynetworks.org/industry/statutory-information
- https://www.theema.org.uk/wp-content/uploads/2015/12/VO-EMA-Buyers-Guide.pdf
- https://www.ofgem.gov.uk/sites/default/files/docs/2010/05/case-study-powerperfector_2.pdf
- https://www.slideshare.net/slideshow/onsite-guide-bs-76712018-electrical-regulations-pdfdrive-pdf/265077876#136