A guide to energy-saving light bulbs

12 November 2014 ( 31 October 2017 )

We look at the types of energy-saving light bulbs and how to choose the right ones for you.



Love them or loathe them, energy-saving light bulbs are here to stay. European Union rules mean that traditional incandescent bulbs can no longer be sold in the UK. So if you’re after a replacement, there's a wide range of energy-efficient alternatives to choose from.

Energy-saving light bulb safety tips...

Here are some key things you need to know about energy-saving light bulbs.

How the technology of energy-saving light bulbs has improved

The good news is, the technology used in this type of lighting has moved on over the past few years. You no longer have to wait minutes for lights to turn fully on, or settle for a cold blue glow – two of the biggest criticisms of energy-saving light bulbs.

They remain, nonetheless, more expensive than traditional incandescent lights: but you can expect to recoup this extra expense in longer lifetimes and lower running costs

According to the Energy Saving Trust, replacing old-style light bulbs in a typical home would cost just over £100 but lead to a £45-a-year reduction in electricity bills.

How do you choose the right energy-saving light bulbs?

Make sure you select the correct fitting for your sockets. Energy-saving light bulbs fit in exactly the same sockets as their traditional counterparts. They are available in bayonets and screw-ins as well as the less common fittings that might be found in bathroom lights or spotlights.

Choosing the right energy-saving light bulbs

Your fitting may have the correct code on it – B22 or B15 for bayonets, or E4 and E27 for screw-ins, for example – so make a note of this or take your old bulb to the shop to get the correct match.

What types of energy-saving light bulbs can you buy?

The two main choices are CFLs (compact fluorescent lamps) and LEDs (light-emitting diodes). Halogen light bulbs are also available, but these are not much more efficient than incandescents.

CFLs are cheaper than LEDs but cost a bit more to run. LEDs, however, can be expected to last for more than 20 years. Some cheaper CFLs may take a few moments to reach full brightness.

Energy-saving light bulbs: frequently asked questions...

How does power vary among different energy-saving light bulbs?

The brightness of incandescent light bulbs depends on their power rating. Typically, for low lighting you would go for 25 or 40 watts, with 100w bulbs used when more light is needed.

With energy-saving light bulbs, brightness is measured in lumens: a 40w incandescent bulb is around 400 lumens, for example. This means going for a 9w CFL bulb or a 6w LED.

The packaging on the new light bulb should tell you what rating of traditional light bulb it is intended to replace.

Warm white or cool white – the choice is yours

In the early days, energy-saving light bulbs were often criticised for the light they produced – some people felt it could be too cold, for example. But you can choose how warm or cold an energy-saving light bulb’s glow is.

Give your home an energy efficient makeover

Warmth is measured in the kelvin temperature scale. An LED light bulb at 2,700 kelvin would be the equivalent to a traditional incandescent bulb – this is sometimes called “warm white”. The higher the kelvin rating, the whiter or bluer the light.

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The opinions expressed are those of the author and are not held by Saga unless specifically stated.

The material is for general information only and does not constitute investment, tax, legal, medical or other form of advice. You should not rely on this information to make (or refrain from making) any decisions. Always obtain independent, professional advice for your own particular situation.