Defra - Nobel House

Defra and Nobel House – powerPerfected

In 2005 a major refurbishment of Nobel House – Defra’s London headquarters – led to its recognition as one of the most sustainable office buildings in Europe. As part of the ongoing powerPerfector rollout across the Defra estate, we were invited to improve the building’s sustainability even further.

The challenge, the solution and the savings

The electrical load in the offices at Nobel House includes lighting circuits, heating and ventilation systems and a combined heat and power system. After evaluation, we installed two 560kVA powerPerfector units (the site has two supplies) both with 8% optimisation settings, over a single weekend in December 2007. See figures 1 and 2 for a before and after comparison.

Topline results

The electricity consumption in the period following installation (when the site’s CHP plant was online) was 13.4% lower than a comparable period the previous year. Overall, there was an 11.9% reduction in average weekly kWh consumption. powerPerfector technology has made sure that the site operates more efficiently, benefits from improved power quality and is protected against common transients (power spikes). The installation took place over a single weekend with a well planned shutdown. There were no reported problems when the supply was reconnected and, with absolutely no moving parts there is no need for maintenance beyond the statutory 5 yearly checks required of all electrical equipment.

90% of Government buildings pay for more electricity than they actually need because of a little-known fact; the power they receive off the grid is usually at too high a voltage. Everything still works of course, but inefficiently.

Voltage Power Optimisation. The less obvious benefits

Reduced maintenance, longer life
All electrical equipment has an optimum voltage at which it works best. A powerPerfected supply delivers that optimum and reduces the strain on your electrical equipment, leaving it to work more reliably and for longer.

Better quality power supply
Some things you may have accepted for years as product faults can turn out to be caused by a poor quality power supply. For instance, the life of incandescent light bulbs is almost doubled when the supply voltage is optimised. Now imagine that in relation to an IT network or an expensive piece of manufacturing equipment.

Missing the penalty kick
Power factor penalty charges – which are now uncapped in the UK – can be avoided if your power factor is above 0.95. If your power factor is at around 0.9 at the moment, powerPerfector could remove your exposure to these charges by improving the electrical efficiency of your site

Lower harmonic distortion and reduced neutral currents
powerPerfectors are able to filter harmonics on the mains incomer. Harmonic distortion is on the increase and can lead to random failures of electronic equipment – particularly computers.

Protection
Common transients – very brief spikes in voltage from the grid – are eliminated by powerPerfector. Transients at this level can cause catastrophic damage to equipment, but smaller, more common transient events will also shorten the life expectancy of electrical equipment over time. The looming energy gap means that the risk of transients is increased – Nobel House is now protected.