AXA - Suffolk House

AXA, Suffolk House – powerPerfected

AXA UK and Ireland is a long-term business focusing on life and pensions, wealth management, protection, health and general insurance and as part of AXA’s continued commitment to carbon reduction, two powerPerfector units were commissioned in July 09.

The Challenge, the solution and the savings

After AXA sent their annual electricity consumption details, it was possible to give a provisional quote for a powerPerfector unit and the energy savings that would be expected. Like most office buildings, Suffolk House has a broad a mix of electrical loads, consisting mainly of lighting, HVAC and computers. AXA had already implemented a number of energy efficiency measures across the site: energy efficient high frequency lighting had been installed; all air conditioning units had inverter drives fitted; additionally all IT equipment was protected by a UPS. The installation was completed on a weekend when there would be no disturbance to the building and there was no noticeable change to the operation of the building.

Topline results

An established method used to quantify energy savings in the context of seasonal variations is known as a “degree days” analysis. Degree days are based on Met Office temperature data, and give a measure of how hard heating or cooling equipment must work to compensate for external temperature. By plotting the weekly kWh consumption against Degree Days and fitting a trend line to this data, it is possible to determine the expected level of electricity consumption for a given number of degree days. The deviation of the weekly kWh consumption values recorded after installation from this trend line shows how actual consumption compares to the expected level each week, and hence quantifies the savings attributable to the installation of the powerPerfector unit. A comparison of these points with the expected level for temperature shows a 6% reduction in average kWh consumption.

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, but 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.