Energy saving light bulbs QA

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 an incredible £140 million a year by leaving lights on unnecessarily.

Doesn’t energy saving light bulbs 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, uses 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 light bulbs 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?

Yes, but they are not as energy efficient as normal energy saving bulbs. So,halogen bulbs should only be used in your existing halogen fittings.

Halogen bulbs come in mains voltage (240 volt) and low voltage (12 volt) varieties. Low voltage bulbs use a transformer which takes the voltage from the mains supply and 'transforms' it to the lower operating voltage of the halogen light. This helps them to use less energy and makes them 35% more efficient than traditional halogens.

Currently, the Energy Saving Recommended scheme only endorses low voltage (12 volt) bulbs: the kind that need a transformer. But there are plans for mains voltage (240 volt) bulbs to be endorsed soon.

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

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.

Remember to always recycle your used bulbs, for example at your local authority's recycling centre.