Cutting waste at the source

Energy efficiency is not limited to how we use energy - efficiency can be improved even before current gets to an electrical motor, computer or heating system by closely controlling supply voltage, says Angus Robertson, CEO of the company that has brought the technique of power optimisation to Britain.

To date the majority of savings in electricity have come from new technologies and control systems downstream of the switch room: with the use of low energy bulbs, management control systems, energy saving initiatives to remind people to turn off power.

Nobody has focused on the raw power quality as it enters the building. Nobody questions power quality until there is some unexplainable occurrence in their electronic or mechanical infra-structure – or have they?

Fortunately the Japanese have, because they had the same economic pressures 10 years ago that we have today. As a result attention was focused on the “source” of electricity to a building (the incoming supply) as well as on voltage level and quality. Technology was invented specifically to save energy and optimise supply quality – “perfected physics,” you might say.

A 560kVA powerPerfector installed at Buckinghamshire County Council’s new offices. For a more detailed explanation of how the technology works see end of article.

In the UK when we plug into the electricity mains, most of us don’t give a second thought about how the voltage level might affect the efficiency of the electrical equipment we use.

But the fact is that 90% of businesses could reduce energy costs by 10-20% with V.P.O. Technology. So why aren’t they ? The simple answer is those that know about it are doing it, the rest need to be educated. Up until 2001/2 this technology was not available in the UK and before then not as relevant as it is today. Soaring energy costs and the necessity to drive down carbon emissions have given Voltage Power Optimisation the opportunity to become mainstream. It is the only technology which can produce savings in cost and carbon emissions, with usually one installation per building, and the added benefit of protecting a building’s total electrical infrastructure.

We know that in the extreme, when the voltage is far too high, light bulbs glow brightly and blow with alarming regularity; whilst with very low voltages, TVs flicker and motors overheat. But there is a broad band in between these extremes where the effects are much more subtle, albeit very significant in terms of energy efficiency.

The consequence of high voltage to the consumer is waste because most electrical equipment is designed to operate at a voltage at the lower end of the ‘statutory’ range. Higher voltages increase losses and result in shorter equipment life. The fact is that, for most businesses, up to 15 per cent of energy is wasted just because voltage is too high.

In Japan the voltage supply level is 100 Volts +/-10% and they are optimising their voltage by reducing it by 2%,4%, and 6% and saving millions.

The technology that does this is called “voltage power optimisation” (VPO). It has been installed in over 300,000 premises and is endorsed by the Japanese government who give 30% grants to businesses to install it.

Now look at the figures – as the statutory range of supply in the UK is between 216 and 252V, and the average supply 242V (Electricity Association) there is the opportunity to reduce it by 7, 8, 9 or even 10% to around the 220V level and still be inside current statutory supply levels.

You might immediately think that by reducing the voltage level on the High Voltage transformer that your business owns is a way to save substantial amounts of money . Unfortunately you would be wrong – at least judging by the results from the implementation of just this technique by two major supermarket chains in the UK.

This happened before the introduction of the new Japanese technology, but it was a bold move that has helped a little. Both Tesco and Sainsbury, leaders in reducing energy use and their carbon emissions, tapped down their supply levels on over 300 transformers by an average of 5% – but only gained savings of approximately 3 to 3,5%.

These savings, while cheap to implement, do not compare to the greater opportunity to “optimise” the supply and achieve savings of 10% to 20%. Voltage Power Optimisation technology must not be confused with simple voltage reduction. It really is a very different and much more advanced technology.

The following two graphs illustrate what savings have been made when 10% and 9% adjustments to incoming voltage have been made through VPO technology.

A 10% adjustment at a supermarket shows a 16% drop in kWh consumption, and a 12% reduction in maximum demand when comparing the two weeks before and two weeks after installation.

Looking at a more typical office building owned by Land Registry (24 installed to date) on a 10% optimisation there is a 15% reduction in kWh consumption (Comparing 5 days before and after installation).

Buckingham CC have installed a 560kVa unit in their New County Offices achieving 13% savings so are rolling out the technology to their other sites. Wycombe District Council have achieved 20% saving at their offices, Buxton Press have installed an 830kVa unit and have also reported 13% savings. Tesco have installed over 70 units, Hilton Group have six installations with more in the pipe line, Abbey, BP, Orange and HBOS all have installations – and the list goes on. All these companies have a strong commitment to our environment and reducing their Carbon footprint.

The economics are, of course, key to the success of any energy saving technology and whilst some of the greener companies may show support for wind and solar technologies with paybacks of 10 years or more many companies have to look much more closely at the shorter term returns of investment. Here the news is good as typical offices are returning 50% on investment (savings versus cost) and supermarkets 75% plus. These returns on investment are higher than most company’s core investment returns, which is the reason that this technology, with its 10 year warranty, may well revolutionise how we look at “wasteful electricity”.

The increasing pressure to tackle carbon emissions and, with energy costs rising ever higher, to use energy more efficiently is finally producing the technology that the public and private sectors need to really make an impact. Couple this with the support of the Carbon Trust offering SME’s up to £100.000 interest free grants for four years, (subject to qualification), and the excuses for not acting are evaporating.

For more information see

How does powerPerfector’s Voltage Power Optimisation work – and why are the results so much better than simply reducing transformer voltage?

Firstly, it is rare to find an HV transformer with more than 5% reduction capacity – the extra 3% to 5% that would be left has not been taken advantage of. And secondly the technology itself, which has losses of just 0.1% through its entire operating range is a completely different design to anything we have in Europe – here are some basics:

Normal transformer coils are wound from copper conductors, typically in the form of round wire and rectangular strip. VPO however utilises wide copper sheet, rather than wire, of the highest possible purity. Sheet production is a demanding process, requiring large, very accurate machines to roll sheet up to 800mm wide, between 0.05-3mm thick. This is then insulated and wrapped around a uniquely designed flaked silicon iron core. Separate star and delta windings act to generate a strong internal magnetic field that assists in balancing the incoming three phase supply, suppressing harmonics and stopping any transients (spikes) from entering a building.

Interestingly it also improves power factor in a building, as proven in readings taken pre and post installation by Nottingham University’s Environmental Technology Centre, who have tested the technology in their laboratory and confirmed savings of 11.5% on minus 7% optimisation.

Technically, most savings are realised in induction motors and lighting equipment. When you optimise voltage to motors, within their normal operating range, core and winding losses are reduced, so they run more efficiently, with less stress and a longer lifetime. Lighting benefits by being returned to its ‘design’ voltage and brightness, so both current and power is reduced and lamp life is increased substantially.

For further information please email powerPerfector



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