Low-Energy Lightbulbs

Energy Saving is no joke, but have you heard the one about the lightbulb? Well, in this case, it only takes one person to change it, and that person is you!

One easy and cost-effective way to reduce your energy consumption is to replace traditional filament lightbulbs with low-energy fluorescent bulbs. If you’re still using filament lightbulbs, you’re not only wasting energy but also a surprisingly large amount of money.

A 100W filament bulb costs around 20p. To replace this with a low-energy one you’d need to fork out around �3, but this new bulb will last ten times as long as the filament one, so only costs �1 more than the 10 normal bulbs you’d need. But, because it uses less electricity, it will save you more than �50 over its lifetime.

To see how the costs stack up, the table and graph below compare running a normal lightbulb with running a low-energy bulb:

Traditional Filament Bulb Low-Energy Bulb
Bulb Cost �0.20 �3.00
Bulb Lifetime 1000 hours 10000 hours
Bulb Cost per 10000 hours �2.00 �3.00
Cost of Electricity per hour �0.008 �0.002
Total Cost for 10000 hours �82 �23

Graph of Lightbulb CostsYou can buy low-energy lightbulbs at all sorts of places. The prices above are just a rough guide, and are based on those from Tesco and Screwfix. You may be able to get them cheaper elsewhere, such as from your electricity provider for example: Powergen for example will supply low-energy bulbs at just �1.50 each, and you can order them by text message.

Obviously, the more a particular light is used, the greater will be your saving in money and energy if it’s replaced, so replace first those bulbs that get the most use. If you can make better use of natural light, by opening the curtains rather than switching on a lamp for example, that’s even better.

Low-energy bulbs do use more electricity when you first turn them on, but in just one minute they’ve already saved enough to repay this. And of course all bulbs use much less energy when they are switched off. Leaving the lights on in rooms you are not using is a waste of your own money.

Some people don’t like the low-energy bulbs, either because they look a bit different, or because they’re slightly dimmer for a few seconds when turned on until they warm up. Both of these concerns can be addressed with more specialist bulbs which, although they cost a pound or two more, will still save a lot on your electricity bill.

As well as saving money you’ll also be helping reduce climate change. We can work out how much of a “carbon saving” you’ll make by doing a calculation similar to this one from The Carbon Trust. If you used this one bulb for two hours a day, by changing it you’d prevent 23.5kg of CO2 being released every year. To quote another site discussing the benefits of low energy bulbs: “Over their lifetimes, they’ll prevent the release of between 1,000 and 2,000 lbs of carbon dioxide from coal-fired power plants; the production of approximately 25 milligrams of plutonium from nuclear plants; or the use of 1.25 barrels of oil.”

So, when your next electricity bill arrives, and it has gone up again because of price rises, rather than just accepting it do something about it, and sort out your lightbulbs.

For further analysis, including a discussion of the ethical and environmental credentials of a number of lightbulb manufacturers, see the article titled “Switched On” in Ethical Consumer, July/August 2005, pages 28-29.