Exploiting controls to halve lighting energy use

Lighting is a major user of energy in commercial buildings — and much of that energy is used unnecessarily. Neil Jones highlights the benefits of controlling lighting.The International Energy Agency was mandated by the G8 Gleneagles Plan of Action to identify strategies for a more sustainable energy future. It recently issued its report which has come to some conclusions that are most significant to the lighting industry. In particular, it says if rapid action is not taken, the amount of energy used for lighting will be 80% higher in the year 2030 than today. The report says that significant savings can be made simply by making better use of current lighting technology. Enormous potential Claude Mandil, executive director of the International Energy Agency, said at the launch of the report. ‘This important work shows that the potential for energy savings in lighting is simply enormous and can be achieved with technologies that not only are readily available in the market, but economically competitive during the life cycle of the product.’ The comprehensive report is the first detailed global analysis of energy used by lighting and includes a thorough review of technologies and policies which can reduce it. Mr Mandil said: ‘In the current lighting environment there are enormous sources of waste. Light is routinely supplied to spaces where no one is present. Over-lighting occurs frequently. While the problem is global, we have the means to address this waste now.’ Controls that are available on the market now are affordable, cost effective and will ensure that interior lighting is delivered only when it is really needed. Before looking at this in detail, consider the fact that we all try and keep unneeded lights switched off at home to save wasting energy costs. However, the amount of energy wasted on the domestic front is dwarfed by the tremendous amount of unnecessary use of lighting in office buildings. A survey by architects Gensler, stated that some 27% of fuel burnt in offices is wasted. In fact. lighting can account for up to half of a commercial building’s electricity costs. With electricity usually accounting for half of the total energy bill, there is the potential to save 25% of the entire electricity load. A stroke Needless use of office lighting can be eliminated at a stroke by using efficient and cost-effective lighting-control systems. This technology has been available now for several years and has demonstrated its ease of installation and reliability in use. The essence of lighting control is to ensure the lights are on only when they are required and always deliver the optimum brightness levels. Presence-detection lighting controls save energy by ensuring that lights are never left burning needlessly in areas that have been vacated or where there is already enough natural light. These are sophisticated yet discreet controls which use a variety of detection technologies — passive infrared, microwave, ultrasonic — to continuously monitor working areas and detect the slightest movements that signify occupants are present. Photocells can be built in to measure the natural light available and tell the luminaires whether or not to switch on, and at what levels of brightness. For integrated and intelligent building-wide lighting control, a managed lighting system offers the most efficient, cost-effective and installer-friendly solution. A managed lighting system allows groups of luminaires to be individually controlled in pre-determined work zones, in an open-plan office for example. Contractors may feel that the more sophisticated the lighting control system is, the more complicated and time consuming it will be to install and commission. They would be wrong. Ensure the lighting-control system specified has no central PC with complex software to deal with and that it employs a low-speed communication protocol. This makes the system much more robust as well as easier to install as the bus wires can be run in the same conduits and/or containment as mains wiring, adding another level of installation simplicity. Software addressing is a minefield for even the most competent and computer-literate installers. With central PC-driven systems, contractors have to install individually pre-addressed equipment in particular locations throughout the building. This task is laborious, and needs the careful marking on drawings of every single piece of equipment, giving a lot of scope for error. Also, if a unit fails, the replacement needs to be factory preset to the correct address before it is refitted on site. To avoid all this, look for a lighting-systems manufacturer that turns this process on its head so that no piece of equipment taken to site — and that includes emergency testing units as well as lighting controls — needs to be pre-addressed. Equipment can be simply installed and then addressed during commissioning, so it does not matter which individual piece of control equipment goes where, as addresses are not assigned until installation has been completed. The International Energy Agency’s assertion that wasteful use of lighting can be significantly reduced using technologies that are readily available in the market now is indeed true. Neil Jones is managing director of Ex-Or Ltd

The reality of delivering lighting energy savings Ex-Or Ltd is supplying lighting controls throughout the University of Manchester, the UK’s largest single-site higher-education institution. Faced with escalating energy costs of up to 80% and the requirement to reduce carbon emissions, this university sees energy conservation as a critical factor in its building programme. The installation of energy-efficient lighting, together with energy-saving lighting controls, is regarded as a major contributory factor in helping to curb the soaring energy bill. ‘Our total energy budget next year is £15 million, and £9 million of that is accounted for by electricity,’ said Chris Cunningham, Manchester University assistant mechanical and energy engineer. ‘We estimate that lighting alone accounts for around 50% of the electrical load. With 10 000 staff and 35 000 students it is equivalent to the entire lighting load of a typical town.
EXTRA PICTURE

‘Having installed a variety of Ex-Or control systems in a number of new-build and refurbishment projects, we have seen the dramatic cuts in energy costs that automatic and efficient lighting control can deliver. Now we are embarking on this unprecedented capital investment building programme, we have decided that each and every building involved will benefit from automatic lighting control.’

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