Main navigation

Frequently asked questions

You're bound to still have some questions about energy saving lightbulbs. Here, we've answered some of the most common queries - and shattered several popular myths along the way.

Doesn't switching lights on and off use more energy than leaving them running?

No. Switching on an energy saving bulb only uses the same amount of power as leaving it on for a minute or two.

Turning the bulb on and off repeatedly may shorten its life, but normal household use shouldn't cause any problems. In fact, Energy Saving Recommended bulbs are tested through 1,000s of cycles of switching.

However, to help it last as long as possible, it is best to leave it on for a 'stabilising' period of 10 to 15 minutes at a time.

And if you're still using traditional bulbs, remember to switch them off every time you leave a room unoccupied. In the UK alone we waste more than an incredible £175 million a year by leaving lights on unnecessarily.

Don't energy saving lightbulbs take a long time to light up?

No, most modern energy saving bulbs take little more than a few seconds to warm up to full brightness.

This short warming up process is due to the way they work. An electric current is passed through gas in a tube, making the tube's coating glow brightly. In traditional bulbs, the current is passed through a wire which heats up and produces light straight away. What makes them incredibly inefficient is that 95% of the electricity used is lost in the production of heat.

Energy saving bulbs, by contrast, use the same efficient technology as fluorescent lights - but are more compact and use even less energy.

Producing an energy saving bulb must take more energy in the first place than making a standard bulb. At the end of the day, doesn't that make it inefficient?

Again, no. Because of its clever technology, an energy saving bulb might take more energy to make than a traditional bulb. But the energy saved by the bulb over its lifetime far outweighs this energy consumption.

Don't traditional bulbs give a better quality of light?

For technical reasons, the glass used to house energy saving lightbulbs has to be opaque - not totally transparent. In other words, the light quality of energy saving bulbs can't be directly compared with that of clear traditional bulbs. Compare them with soft tone traditional bulbs, though, and you won't see any difference.

Are halogen bulbs more efficient than traditional bulbs?

Halogen bulbs in the home consume less energy than traditional bulbs (typically 20W-50W for halogen bulbs compared with 40W-100W for traditional bulbs). However, rooms lit with halogen bulbs usually have more fittings than rooms lit with traditional bulbs or energy saving bulbs. Therefore, they will use more energy.

If you have halogen lighting in your home you can buy Energy Saving Recommended halogen bulbs. There are currently two of these on the market: Philips Masterline and Osram Decostar. They use around 30% less electricity than traditional halogen bulbs.

Lots of my lights have dimmer switches. Can I fit them with energy saving bulbs?

Most energy saving bulbs aren't fully compatible with dimmer switch circuits at the moment. A standard dimmer switch will simply make the bulb flicker: annoying for you and not good for your bulb.

The Osram Dulux El Dim is currently the only fully dimmable energy saving bulb. However, there are plans for more to be developed later this year.

There are also energy saving bulbs that can be used with 'staged dimming'. This requires a special sort of dimmer with three separate settings - high, low and off.

Is the government really banning traditional incandescent bulbs?

There is a proposal for a voluntary phasing out of traditional bulbs between now and 2011. This will give manufacturers and retailers enough time to develop additional products that will take their place.

Don't CFLs contain mercury? And isn't that bad for the environment?

Energy saving bulbs contain only tiny traces of mercury - imagine a pellet smaller than the tip of a biro. What's more, in the long term, CFL technology will actually help less mercury to pollute the air.

This is because burning fossil fuels like coal is the biggest source of mercury in the air. And as energy saving bulbs use 80% less electricity than a traditional bulb, they mean far less mercury overall.

Recycling your energy saving light bulbs

Energy saving light bulbs are part of the Waste Electrical and Electronic Equipment (WEEE) initiative which means that those who sell these products must provide information to the public on how they can be recycled. You could speak to the retailer you purchased your energy saving light bulb from about how to recycle it or alternatively you could contact your local authority to see if they will recycle energy saving light bulbs. If you don't know who your local authority is you can find this out at Directgov

You can also find out more about disposing of energy saving light bulbs at Recolight.co.uk

Find out more about WEEE

Page tools

  • Email this page
  • Rate this page

    Average rating: 3 - OK

Register for updates

For regular email updates please submit your email address below.

Email address:

Help and advice

Call 0800 512 012 for free, independent and local energy saving advice

Click here to request a call back from your local advice centre.