• conventional incandescent filament lamps which have a low purchase price, low efficiency and whose life is approximately one year of usage;
• compact fluorescent lamps (cfl) which produce light in a much more efficient manner converting up to 80% of the electricity into light and whose life can be up to 15 years;
• cfls are therefore commonly called ‘low energy lamps’;
• a longer life means fewer lamps to buy and change so generating less environmental waste;
• the light quality of cfl lamps has improved considerably so that the colour rendition is now close to daylight; some lamps are available with different colour rendering (from cold to warm light).

Cost

The cost of low energy lamps now depends primarily upon their life with the cheapest being those with a 3 year life, typical cost £2 to £3, and the most expensive having a 15 year life with a typical cost of £6 to £8.

As these lamps have a much lower running cost (only 20% of conventional lamps) one can recover ones initial cost within 3 to 12 months depending upon the life of the lamp and thereafter save up to £6 per lamp per year.

Good practice

• during daylight hours use natural light as much as possible;
• use an appropriate type of light fitting and lamp for the work being done;
• use indirect lighting that is projecting light onto walls or ceiling only when appropriate as it causes the loss of at least half the light emitted;
• switch off lights when not being used;
• install low energy light bulbs in places where lamps are intensively used or are difficult to replace.

For hints on saving energy with other appliances please click here.