Energy saving light bulbs: How to buy energy saving light bulbs
- The different types of energy-saving light bulb explained
- What fittings and shapes energy-saving light bulbs come in
- Jargon busted - what's a watt these days?
Energy-saving light bulbs
Traditional incandescent light bulbs are being phased out by September 2012, which means energy-saving light bulbs are rapidly becoming the only light bulb choice.
But there are three entirely different types to choose between - and a big difference between the best and worst performing bulbs. Read our independent test results to find out which bulbs became Best Buys - and which didn't.
As lighting accounts for around 15% of the electricity bill in most homes, each energy-saving light bulb could save you up to £10 a year. And by getting a high-performing bulb you won't be at the mercy of bulbs that are dim at start-up or don't last long.
Traditional light bulbs are being phased out and replaced with energy-saving bulbs
Light bulb types - CFLs, halogens and LEDs
Energy-saving light bulbs come in three types.
Compact fluorescent lamps (CFLs) - the most common type, use 60-80% less energy than an incandescent bulb, and generally the cheapest option.
Halogens - use 20-30% less energy than an incandescent, although they have a similar tungsten filament.
LEDs - use 90% less energy than an incandescent but much more expensive than a CFL.
CFL wattages and incandescent wattages - old and new money
Watts used to be the way to tell bulbs apart when the only choice was between incandescent bulbs.
But watts are a measurement of power - and so of how much power a light bulb draws - rather than of how bright a bulb is.
Lumens are the unit used to measure light output, or brightness. So it's the lumens figure you need to have in mind when buying a new bulb.
Our table shows lumen ratings on the left, the equivalent wattage of incandescent bulb next, and then the equivalent wattages for CFL, halogen and LED energy-saving bulbs. The packaging of each bulb usually display three figures:
- lumens
- wattage
- equivalent incandescent bulb wattage.
| Wattage and maximum lumen output comparison | ||||
|---|---|---|---|---|
| Maximum light output measured in our tests | Incandescent bulb wattage | CFL wattage | Halogen energy saver wattage | LED wattage |
| 200-300lm | 40W | 7, 8 and 9W | n/a | 5 & 6W |
| 300-400lm | 40W | 7, 8 and 9W | 28W | n/a |
| 400-500lm | 40W | 8, 9 and 11W | n/a | n/a |
| 500-600lm | 60W | 8 & 11W | 42W | n/a |
| 600-700lm | 60W | 11W | 42W | n/a |
| 700-800lm | n/a | 11 & 15W | 52 & 53W | n/a |
| 800-900lm | n/a | 15W | 53W | n/a |
| 900-1000lm | 100W | 15W | n/a | n/a |
| 1000-1100lm | 100W | 15 & 20W | n/a | n/a |
| 1100-1200lm | 100W | 20W | n/a | n/a |
| 1200-1300lm | 100W | 20W | n/a | n/a |
Light bulb fittings
Energy-saving light bulbs fit in ordinary light fittings. They come in three fittings:
- small bayonet (B15) - although these are very rare
- bayonet (B22)
- small screw (E14)
- large screw (E27)
- two pin GU10s.
Light bulb shape
You can get energy-saving bulbs in an increasing variety of shapes:
- candle - for chandeliers
- stick - the commonest type of CFL bulb when they first came on to the market, now generally much smaller
- bulb - similar in shape to traditional incandescent bulbs, but larger
- spiral - effectively a stick shape of CFL in a twist.
- Behind the headlines: energy-saving light bulb fact and fiction
- Find out how much money you could save with energy-saving light bulbs
- More ways to save electricity
