Why act?

Lighting makes more difference than you might think. People now have many lights, especially in kitchens. Lighting technology is changing rapidly. Lights are more efficient and last much longer. Old-fashioned lights lasted about a year. The newest ones last 25 years or so. We can save energy and save money quickly by changing to new bulbs.

The old-fashioned light bulb

The old-fashioned light bulb was an incandescent filament in a light bulb filled with tungsten. Tungsten incandescent light bulbs are being phased out. Halogen light bulbs were also incandescent and also used a lot of energy. They were mostly for spotlights.


Compact fluorescent lamps (CFLs) took over from incandescent light bulbs a few years ago. There are now CFLs to fit most standard light sockets.

CFLs are the ones that used to take a moment to light up. The newer versions don’t have this delay.

CFLs use only a quarter of the electricity to provide the same amount of light as an incandescent tungsten light bulb. CFLs last about 10 times as long as an incandescent bulb (10,000 hours compared with 1,000 hours).

Using a 25W CFL instead of an equivalent 100W incandescent bulb for four hours a day can save 64 kilos of CO2 a year.

LED lights

LED (light emitting diode) lights are even newer than CFL lights. They are more expensive than CFLs, but they last longer, are more easily dimmed, and are better than CFLs for spotlights.

LED lights use less energy than CFLs and last about 30 times as long as an incandescent bulb (30,000 hours).

Using a 16W LED instead of an equivalent 100W incandescent bulb for four hours a day can save 74 kilos of CO2 a year.

How to know what you’re buying

When you buy a bulb, look at the packaging to check:

  1. 1.            Colour “temperature: CFLs and LEDs have a colour “temperature” on the packaging. For your home, you’re likely to prefer an index of more than 80 and a colour “temperature” which is warm white or soft white.
  2. Brightness (not the wattage equivalent): CFLs and LEDs, like the old incandescent bulbs, are labelled with their power requirement in watts. Confusingly, this isn't the same as the brightness, which is measured in “lumens”, also shown on the packaging. A 60W tungsten incandescent bulb produced about 750 lumens. Labelling on CFLs and LED lights is changing to fit people’s experience of using them, which is affected by the direction of the light. For example 6W GU10 sunken spot-lights of the type found in many kitchen ceilings seem brighter.

Take action

  • Go to your local hardware shop, supermarket or lighting shop and educate yourself about the choices.
  • Do a room-by-room inventory of all your lighting fixtures. If you still have incandescent bulbs (whether tungsten or halogen), make a note of their wattage so that you can buy a CFL or LED with the equivalent power. In particular, replace those ubiquitous halogen sunken spotlights found in kitchen ceilings – LEDs will cut your CO2 emissions dramatically and cut your energy bills.
  • Note which fixtures have bayonet and screw sockets, their size or type, which require dimmable bulbs, and which will be used outdoors (as these require special CFLs or LEDs).
  • Buy samples of what you think you’ll use. Do not rely on the labelling only. There are a confusing number of variables. Buy one example and test it to see if you like it. In particular, try out LEDs as replacements for halogen and CFLs. They will probably seem brighter than the label implies. If you are not satisfied with the result, wait a while. LEDs are getting even better and cheaper.
  • Try out your samples in different rooms to check that you will be happy with the result. For some purposes, where particularly good light is required, a slightly higher wattage bulb may be needed. Elsewhere, look for opportunities to use bulbs that are less bright.
  • Purchase and install the CFLs or LEDs you need.
  • Needless to say, don’t forget to turn off the light as you leave a room (unless there is someone in it!)

Time & materials

  • An hour or two to complete your survey, and to buy and install sample new CFLs or LEDs.
  • Another hour or two to revisit the shop, buy the lamps you need. And install them.


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