Switched On to Savings

15 October 2010

With local authorities under pressure from ‘cuts’, the installation of lighting controls at Portsmouth Council HQ offices demonstrates the potential for real savings in energy and costs

THE INSTALLATION OF EX-OR lighting controls throughout Portsmouth City Council's civic headquarters has led to the Council cutting its lighting bill by an estimated £39,000 a year. This has been achieved by the automatic elimination of the unnecessary use of its office lighting.
The energy saving being made has also enabled Portsmouth City Council to cut its carbon footprint and make a serious contribution to its Carbon Reduction Commitment obligations. The Council has cut its annual energy consumption for lighting in the offices and corridors before the Ex-Or installation from 1,259,398 KWh to 655,211 KWh. This represents annual cost savings of approx £39,151 and annual CO2 savings of 326 tonnes.
Within the 31,679m glass-fronted civic offices on Guildhall Square, built in the 1970s, more than 1,500 staff are at work across its seven floors. Before the Ex-Or installation, the lights were on for much longer than the core 9 am to 5 pm working day. Portsmouth City Council electrical services manager Jamie Cake said lighting controls were needed that would ensure light was delivered only where and when it was required.
After a competitive tender, the Council chose Ex-Or, part of Honeywell, to supply Gold Series LightSpot detectors for installation throughout the open plan office areas. LightSpot Standard Series detectors were also supplied to control the lighting in corridors and lift lobbies.
These discrete, flush-fitting units control the lighting by both presence detection and photocell control. The microwave Gold LightSpot detector provides 360o movement detection capability. When occupants are detected, LightSpot ensures the lights remain on until such time as the monitored area is vacated. It then automatically switches the lights off. Integral photocells monitor levels of natural light, ensuring the lights only come on when natural light levels are low.
Said Jamie Cake: "The lighting control solution we required also needed to be flexible, so that changes in workspace areas within the open plan office areas would not require visits by electricians to alter light fittings or controls."
Now the Ex-Or LightSpot controls have been installed by the Council’s M & E contractors, Kier, it is a simple matter to change lighting patterns whenever workstation layouts are altered. A simple remote control unit is pointed at the LightSpot controls to change the parameters at the touch of a button.
"Portsmouth City Council is an organisation that takes its environmental obligations very seriously," said Jamie Cake. "It was unacceptable that energy was being wasted by the lights remaining on when they were not needed. The Carbon Reduction Commitment is designed to reduce the carbon emissions made by larger commercial and public sector organisations like ourselves by 1.2m tonnes of carbon per year by 2020. This reduction in lighting usage has given us a head start in helping us meet our CRC commitments. Not only that, but the installation has led to us cutting an estimated £39,151 a year off our electricity bills. We are also saving a significant amount in maintenance costs as we do not have to replace the fluorescent tubes as frequently. Put these two factors together and we estimate the installation will have paid for itself within four years, and will continue to deliver energy cost savings for many more years to come."
He added that the specification of the Ex-Or LightSpot controls were "future- proofed". The Council plans to change over to more energy efficient digital lighting ballasts in the future, as and when funds become available which will enable the lighting controls to automatically dim and brighten the lights in addition to providing the automatic switch on and off function