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Why is the UK paying more for its voltage than Europe?

The UK has a higher voltage compared to mainland Europe, leading to higher costs.
The average voltage supply in the UK is approximately 242 volts, while in mainland Europe, it is closer to 220 volts.

All CE marked electrical equipment is designed to work normally at 220 volts. However, average grid supply in the UK is 242 volts. Stuart Hawkwood, Founder and Managing Director of voltage optimisation specialist Powerdown220, explains the historical reasons for the UK’s high voltage and the costs to UK business and consumers.

Traditionally, grid supply in the UK and Commonwealth countries was around 240 volts, whereas on Continental Europe it was lower at 220 volts. In 1993, to avoid manufacturers having to make two separate sets of equipment to operate in both jurisdictions, the European Union decided to harmonise voltage at 230.

Following this decision, the UK National Grid must supply voltage at 230 volts, plus 10% or minus 6%. Another way of expressing this is to say that the supply of voltage to any premises in the UK must range between 216 volts to 253 volts. This harmonisation decision permitted the UK to continue overvolting, as the traditional 240 volts supplied stayed within the permitted range. So what changed?

Change and opportunity

Thirty years on from the 1993 voltage harmonisation agreement, the average voltage supply in the UK is approximately 242 volts. On mainland Europe, it remains closer to 220 volts. What has changed is the way electrical equipment is designed and manufactured.

Since 1993, all equipment intended for use within the European Union must display the CE mark indicating compliance with the relevant standards. Standards for electrical equipment stipulate that it must work at 230 volts, plus or minus ten percent.

The permitted range of variation is therefore from 207 to 253 volts. As a consequence, your electrical equipment will work perfectly well at 220 volts and herein lies the opportunity.

If you can lower your voltage, you will also lower your energy bills and your carbon footprint. Is there any drawback to reducing your voltage to 220 volts? You will be surprised to discover that not only is there no drawback to lowering your voltage, but it will almost certainly guarantee an increased lifespan for your equipment too, meaning you will enjoy reduced maintenance costs as well as lower energy bills.

How much is the UK paying for its higher voltage?

Those who are less familiar with the history of the UK’s over-voltage might ask why the country decided not to lower its voltage in line with the harmonisation decision, given this would result in the UK consuming less and therefore paying less for its electricity.

Ultimately, it was not practicable for the UK to lower the supply from the National Grid to the 220 volts seen throughout Europe, which made compromising at 230 volts the only viable way of solving the problem faced in 1993.

The cost is not spread evenly, as voltage supply varies. This is shaped by a range of factors, above all demand and proximity to local infrastructure. Checking and measuring your own voltage is relatively simple to do. You can measure your voltage supply right now by using a low-cost energy meter that plugs into a standard 13A socket.

If you are in the minority, you might find that your voltage is closer to 230 than 240, in which case you do not need to worry about the costs of over-volting. Given the average is 242 in the UK, it is far more likely that your supply is above 235, in which case there is almost certainly a significant opportunity for you to enjoy substantial savings on your energy bills by installing a voltage optimiser and lowering your voltage.

The opportunity is greatest for high consumers of electricity. For example, if you measure your voltage supply from the Grid at around 235 volts and you are using over 300,000 kWh of electricity on an annual basis, the opportunities for savings are significant.

What can you do?

Installing a voltage optimiser will reduce your voltage to 220 volts, which is more in line with average grid supply on mainland Europe. Not only will your CE marked equipment still work perfectly, as it is designed to, by having less voltage running through it, you reduce the risk of burning it out.

In fact, according to UK Wiring Regulations BS7671, ‘‘any linear appliance with a design voltage of 230V, when required to work at a constant voltage of 240V and above, will consume more energy and suffer a shortened working life of up to 46%.’’ Although it is difficult to quantify the savings that can be achieved by reduced maintenance costs, it is inevitable that if your current supply is over 240 you are damaging your equipment.

I stated previously that there were zero drawbacks to lowering your voltage. While that is true in principle, there may be rare exceptions where lowering the voltage exposes other problems you weren’t aware of. For example, if you had an extractor fan that was bunged up with grease, that extra voltage might actually be keeping it going even if you are paying more for it. Lowering your voltage might mean the fan stops working, but I would suggest the problem here is the fan and not the optimiser.

The only real drawback then is the cost of installing the optimiser. Traditionally, that is one factor that has put off businesses from investing, even when they are aware of the benefits of VO. However, the recent surge in energy prices has proved a game-changer for many businesses, as it reduces the return of investment to around 18 months.

As a nation, we are all paying for over-volting our electrical equipment. In spite of the 1993 harmonisation of voltages, we are stuck with higher electricity bills, paying for voltage we do not need, and more than likely damaging our equipment prematurely. 

If your voltage supply is 235 or above, or if you are a high consumer of electricity, it is worth being aware of the options you have for mitigating the energy crisis. Voltage optimisation is an established technology that can reduce the voltage level from the grid supply to match the needs of your equipment, sparing your pocket and the planet in the process.

Stuart Hawkwood

Founder and Managing Director of Powerdown220

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