In the UK, the old style light bulbs, the filament type or incandescent light bulb, are being phased out, and now the preferred option is to buy and fit Energy Saving Lamps, which are also known as compact fluorescent lamps.
It makes sense to replace old inefficient tungsten filament bulbs, as they are heavy users of electricity, of power. The basic principle of filament bulbs is to heat a coil (filament), the heated coil glows which produces light, the hotter the coil, the more light will be produced.
incandescent light bulb
So, the byproduct of producing light is the heat, which is wasted energy.
New technology lamps, LED‘s and Energy Saving Lamps work on different principles.
LED‘s are illuminated by electrons that run through semiconductor material, the diode, they do not have a filament, therefore do not produce heat, use less electricity and will never burn out.
Light Emitting Diode (LED)‘s
Energy Saving Lamps work by a completely different process called fluorescence. In principle, electricity is passed through two electrodes, one each end of a white tube which contains a mercury gas. The electrons produced by the electricity passing through the electrodes at each end of the white tube, strike the mercury gas which generates energy or ultraviolet light which unfortunately we humans cannot see. But, the white glass tube is coated with chemicals called phosphors, and when the ultraviolet light hits the phosphors there is a reaction and more energy is produced in the form of photons which we can see as light.
Energy Saving Lamps
So with LED‘s and Energy Saving Lamps, little heat is generated and wasted. It is said that 90% of the energy used in the filament type or incandescent light bulb goes on heat. Energy Saving Lamps are said to use 80% less energy and last 10 times longer than old style lamps.
There are the downsides with LED‘s and Energy Saving Lamps. The Energy Saving Lamps use mercury, and when discarded at the end of their life, the mercury gas can enter the environment and is harmful to it, therefore any old fluorescence lamps should be discarded responsibly.
LED‘s are now being fitted to torches, car lights and traffic lights. As they use minimal energy, last a very long time, fitting LED lights to street furniture is very cost effective. But as LED‘s produce no heat, it was found that any snow or ice that formed on traffic lights was not melted, and thus drivers did not see the signals which resulted in accidents. People have to be employed to clear the snow and ice from the street furniture, rather defeating the cost saving I think.
Great ideas for saving energy and the environment.