Advances in lighting

Another technical step change will occur in the sphere of lighting. Already the days of the compact fluorescent light are numbered. It will be made redundant by developments in light emitting 'photonic' materials. Solid state light emitting diodes (LEDs) are based on the quantum principle that an atom's electrons emit energy when they jump from a high energy level to a lower one. By adjusting the 'band gap' between the two levels, light of different colours can be emitted. LEDs are a by-product of semi-conductor technology and produce light at much lower watts per lumen than conventional systems. They also have a size advantage. For example, an LED of less than one square centimetre would emit as much light as a 60 watt bulb using only 3 watts. Whereas an incandescent lamp achieves an efficiency of 10-20 lumens per watt, LEDs are predicted to realise 300 lumens per watt. They are almost unbreakable and have a life expectancy of 100 000 hours. It is estimated that, if existing light sources in the US were converted to LEDs, there would be no need for new power stations for 20 years, assuming the present annual rate of increase of consumption of 2.7 per cent. As lighting accounts for most electricity used in most offices, LEDs will offer significant savings in annual costs. However, a note of caution. According to Scientific American 'White LEDs are possible, but affordable ones powerful enough to illuminate a room remain at least a decade away' (February 2001). Nevertheless, what all this amounts to is that wholly electricity autonomous buildings should be an economic reality around a decade from now, avoiding the necessity of being connected to the grid.

Renewable Energy Eco Friendly

Renewable Energy Eco Friendly

Renewable energy is energy that is generated from sunlight, rain, tides, geothermal heat and wind. These sources are naturally and constantly replenished, which is why they are deemed as renewable.

Get My Free Ebook

Post a comment