Switch to Energy Saving Lamps and cut CO₂ Emissions

The Facts

Only about 5% of the energy used by a normal tungsten filament lamp is converted into light. The other 95% of the energy is dissipated by heat. On the other hand, modern energy saving fluorescent lamps convert about 20% of the used energy into light with the remaining 80% converted to heat.

The following table illustrates the difference between normal tungsten filament lamps and modern energy saving fluorescent lamps.

How Energy Efficient are Energy Saving Lamps?

On the face of it, the so-called "energy efficient lamps" do not appear to be energy efficient as they only convert about 20% of the energy used to light. Clearly, there still is much that needs to be done by lamp manufacturers to improve the efficiency of lamps.

However, because the function of lamps is to produce light, we should not compare tungsten filament lamps with electronic energy saving lamps of the same electrical power. We need to compare them based on the same light output.

Using an example of a 100 Watt tungsten filament lamp, it gives out just under 5 Watts of light as it is just under 5% efficient. For an electronic energy saving lamp to give out just under 5 Watts of light, it needs to have a rated power of just under 25 Watts as it it around 20% efficient. This is summarised below.

For a detailed analysis of the pros and cons of low energy vs incandescent lamps see the article that was written as a result of an impending ban on incandescent lamps in Australia.