AS the nights are drawing in, you may be using your lighting more and more, so it’s a good time to think about energy saving bulbs.

Nov 6 2007 by Karen Wilson, The Journal

Here are some frequently asked questions:

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 £140m a year by leaving lights on unnecessarily.

Do energy saving lightbulbs take a long time to light up?

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 uses more energy than making a traditional bulb. Doesn’t that make it inefficient?

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.

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 (240volt) 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 but there are plans for mains voltage (240 volt) bulbs to be endorsed soon.

Don’t energy saving bulbs 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. In the long term, energy saving bulb technology will actually ensure less mercury pollutes 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 is produced.