About low-energy light bulbs: introduction

Low-energy light bulbs, otherwise known as 'energy-saving lightbulbs', now come in a huge variety of shapes and sizes. The majority are of a type called compact fluorescent lights (CFLs), but increasingly there are also low-energy halogen bulbs, and LED (light-emitting diode) bulbs. The style and performance of low-energy bulbs have improved dramatically in the last few years. So, compared with the earlier versions, they work better, they look better, and they cost less. Whatever types of bulbs you use to light your home, you can now find stylish energy saving equivalents – so no excuse – why not switch all your bulbs to energy saving ones?

Variety

Low energy light bulbs are now available in a wide variety of fittings, shapes and sizes. As well as spirals and the traditional sticks, you can get traditionally shaped bulbs, or round and candle shaped, with bayonet or small or medium screw fittings. There are also replacements for halogen bulbs, reflector bulbs and even dimmable ones. If you think energy saving bulbs give off a cold, harsh light, try “soft tone” bulbs which give a warm glow rather than a cold light.

Power consumption (wattage)

Energy saving bulbs are available at the equivalent wattage for all normal incandescent bulbs, but use 80% less electricity. For example an energy saving bulb only uses 20 watts of power to create the same light as a standard 100 watt bulb.

Wattage conversion table

If you still think low energy light bulbs aren’t bright enough, try the 30 watt one which is equivalent to 150 watts!

Cost and savings

The cost of energy saving bulbs is constantly falling. The average price of the stick and spiral CFL bulbs is now less than £1, while the more specialist ones cost up to £10 or more. Depending on how long your lights are on every day, just one energy saving bulb could save you up to £7 a year on your electricity bills, so even the more expensive ones can pay for themselves in about a year. Because it will last up to 10 times longer than a traditional bulb, it could save you around £60 before it needs replacing. If you fit all the lights in your house with energy saving ones, you could save around £600 over the lifetime of the bulbs. This takes into account the higher cost of low energy bulbs.

How to choose replacement bulbs

Buy energy saving bulbs for your most frequently used light sockets first, and fit in places where access is difficult or dangerous such as above stair wells – because they last longer, you won’t have to change them so frequently. Stick type CFLs, although less attractive, are now cheap, and can prove ideal for some locations.

If the lights are used outdoors, they should be enclosed in a sealed unit to provide thermal and environmental protection, as their effectiveness may be affected by cold conditions. From tests, domed and globe shaped CFLs seem not to dim in cold conditions and their running costs are slightly lower, but they are slower to start than other available CFL shapes.

Phaseout of 'traditional' bulbs

A mandatory EU-wide phaseout of traditional incandescent lightbulbs started in 2009, with the banning of 150W and 100W bulbs. The 60W bulb will bow out from 1 September 2011, and the phaseout is due to complete by September 2012, when 40W and 25W will be axed. These EU rules mean that soon, like it or not, everyone will have to use low-energy bulbs - and take comfort from their reduced electricity usage and consequent lower associated carbon emissions.

What’s wrong with traditional bulbs?

With traditional, or incandescent bulbs, light is generated when an electrical current is passed through a thin metal wire, and the wire becomes hot and emits light. Only 10 per cent of the electrical energy is converted to light, so 95% of the energy that goes into them is wasted as heat. In contrast, the operating systems of energy efficient bulbs use electricity to produce light, not heat. They use the same technology as a fluorescent tube in strip lighting – they are coated with a thin layer of phosphorous powder which absorbs ultraviolet radiation and glows brightly when electricity is passed through gas in the tube.

Electricity consumption

At the moment, lighting accounts for around 16 per cent of domestic electricity consumption, with the average house having around 22 light bulbs. The number of light bulbs, and electricity consumption, is set to increase hugely by 2010. If every household in the UK replaced two incandescent bulbs with low energy bulbs, electricity consumption for lighting would drop by 40 per cent, a saving of 11,985 GWh per annum (more than Sizewell B nuclear power station produces each year).