If someone asks me, what is meant by Best Available Lighting Technology, I usually ask them a question in turn – What is of most importance –is it people or the technology? It is possible to choose one or the other, of a combination of the two. I want to put people in the centre. Good lighting satisfies both visual, emotional and biological functions, so that people should have a feeling of wellbeing when the light is turned on. Several projects about light emitting diodes have commenced through the EU programme Green Light, in which Sweden is participating through the Swedish Energy Authority. This lighting programme is to stimulate companies, municipalities and national authorities to invest in energy efficient lighting. At the same time, a better working environment will be created for the staff.
Should the light in the lift be changed? There are about 120,000 lifts in Sweden which, on average, use 438 kWh annually. According to the Swedish Energy Authority, this energy use can be reduced to almost 54 kWh annually, with LED instead of traditional lighting as in this lift. An American study has shown that lift passengers prefer LED with regard to visibility, comfort, colour rendition and attractiveness. In addition, LED in fittings of low profile can reduce installation space by 10-15 cm. Photographer: Mikael Röhr (top), Nordic Light (bottom)
Suitable in lifts…
Light emitting diodes are not only energy efficient, long lived and a good light source. They are also very small which is extremely important when the space for installing the lighting is limited. Lifts are a good example of these recessed light fittings for general lighting. Compared with traditional incandescent bulbs or fluorescent tubes, LED in fittings of low profile can reduce installation space by 10-15 cm. When a lift is designed, the car can be made lower, which results in the saving of materials and weight and savings in the design of motors and brakes.
The Energy Authority has formed a cluster comprising the companies Örebrobostäder, Riksbyggen, HSB, Fastighetsägarna, Åhman i Åhus Hissar, Nordic Light, ESDE, Cree and Osram Opto for the development and demonstration of lift lighting with LED.
…and in stairways
The firm Örebrobostäder is also engaged on a project in which fluorescent tubes are replaced by LED in 10,000 stairways in blocks of flats. Modern fluorescent tubes today have a luminous efficiency of almost 100 lumen per watt, and are very energy efficient. However, the fittings used in stairways are very simple and reduce the efficiency of the system. The tubes have no reflectors and have hoods that absorb quite a lot of light.
In a short time, LED will have a luminous efficiency of 100 lumen per watt. If the fittings are designed correctly, their life may be about 50,000-60,000 hours. The diodes are fully dimmable and can be quickly and frequently turned on and off. Nor do they, in contrast to fluorescent tubes, contain any
mercury.
It is estimated that the operating time of lights in stairways can in the long run be reduced from 8,760 hours to 1000 hours annually, through turning the lights on and off when needed instead of having them on unnecessarily. Each LED fitting will replace six fluorescent tubes and in this way even more energy will be saved in production, on packaging and transport. This also reduces emissions of carbon dioxide.
Effective in deep freezes
A third application of LED is in fridges and deep freezes.
A deep freeze usually runs at -20°C. This reduces the luminous efficiency of fluorescent tubes by about 60 per cent. In contrast, the luminous efficiency of light emitting diodes increases by about 20 per cent at the same temperature.
The Swedish Energy Authority has therefore initiated a project whose aim is to develop, verify, demonstrate and commercialise LED systems to replace fluorescent tubes in commercial fridge and deep freeze installations. Fluorescent tubes are being phased out of the Swedish market over a period of ten years. It is estimated that the energy use for such installations will be reduced by at least 50 per cent annually.
Green light
Companies, municipalities and authorities are carrying out, through the EU programme Green Light, alterations to lighting installations in 50 per cent of their premises over five years. The alternative is to reduce total energy use for lighting by at least 30 per cent. By investing in the best lighting technology, it is possible to save 30-50 per cent of the electricity used for lighting. The Swedish Energy Authority provides assistance by surveys and needs analyses, training and information, and tools for the calculation of savings. Those participating will be presented at fairs, seminars, conferences, etc.
www.energimyndigheten.se
Author
:
Kalle Hashmi
deals with lighting issues at the Swedish Energy Authority