Energy-efficient light bulbs

Nearly a third of our electricity bill pays for our lighting. Get the low down on bulbs to bring your costs down.

What are they?

Incandescent light bulbs (the classic filament design) have changed very little since their invention in 1879. Around 95% of the energy they use is wasted as heat with only 5% going towards lighting our homes.

The average incandescent bulb lasts just five months to a year. Modern low-energy bulbs (CFLs), on the other hand, require only 20% of the energy incandescents need to produce the same amount of light and can last up to 12 times as long.

How much will it cost?

With special promotions and multi-pack deals, prices can be as little as 49p per bulb (Philips ranges from John Lewis). And although the average price for a single CFL is around £3.50, this will fall as demand increases.

How much cash will I save?

Research by Greenpeace UK suggests an average 15% saving on electricity costs, or around £50 per year simply by changing to CFL bulbs.

The Energy Saving Trust compared a standard 100W bulb and its equivalent 18W CFL bulb. Over the course of their, the CFL cost just £18 (10,000 hours) compared to £73 (just 1,000 hours life).

That’s a £55 saving per bulb.

How much carbon will I save?

As a country, switching from incandescent bulbs for domestic use could see savings of up to 5 million tonnes of CO2 – the equivalent of emissions from a medium-sized coal-fired power station.

A CFL uses 70% less CO2 than an old-fashioned bulb and will save around 38kg of carbon dioxide over its lifetime.

What should I buy?

Like appliances, light bulbs are graded A-G (A being the best) according to their efficiency - so it makes sense to buy 'A' to maximise the savings you’ll make.

As for choice, Homebase sells dozens of different types of low-energy light bulbs.

Before you reach for the light switch…

  • Open the curtains and blinds – you can’t beat natural light, and it’s free.
  • Clean the windows – you'd be amazed how much more light a sparkling pane admits. 
  • Dust the lampshades – lampshades and bulbs covered in dust won’t light half as well.



‘They can’t be used with dimmer switches’ - False!

A standard CFL can’t cope with the change in voltage caused by turning a dimmer and will flicker, but improvements are coming. At present, they will probably be more expensive, but as the technology improves, prices will tumble.

Don’t bin your old bulbs

Energy-saving bulbs contain a small amount of mercury, which is highly toxic. Although most local councils still don’t offer CFL recycling, don’t be tempted to just bin them.

Thankfully, there are a number of shops, including Ikea, that will recycle them. Collect up any that you have, ask friends or neighbours to do the same and take them the next time you go. Companies such as Recyclite will also collect and recycle CFL bulbs.

In March 2007, the government announced it would ban incandescent bulbs by 2011. The introduction of the WEEE directive in January 2007 should mean improved recycling facilities to cope with the increase in CFLs.

Some local councils will accept bulbs for recycling, so it’s worth contacting them first to see where your nearest recycling centre is.

This article is based on an extract from How Can I Stop Climate Change?

Find out other ways to save cash and save the planet with our No cost ways to save energy.