How do energy-saving lightbulbs impact your energy bill and the environment?

Last updated: 8 October 2020

In this guide, you’ll find answers to the following questions:

  • How have lightbulbs changed since they were invented?

  • What energy-efficient lightbulbs are currently available?

  • How expensive are energy-efficient lightbulbs?

  • How do energy-efficient lightbulbs help the environment?

  • How can you use your lightbulbs efficiently?

Why should I care about which lightbulbs I use?

Everyone’s energy bill is slightly different - not all of us have a tumble dryer using energy or games consoles plugged in all evening. One thing we all have in common, though, is lighting. Whether you have overhead lights, floor lamps, table lamps, lava lamps, extractor fan lights, lights for your garden, lights activated by Alexa or any other type of lighting, around 15% of our bills tend to be attributed to our lights.

As is the case with pretty much everything we use around the house, we can stand to be more energy-efficient when it comes to our lights. There are measures we can take surrounding how often the lights come on and how long they’re on for, such as putting exterior lights on a timer or making them motion-activated, and remembering to turn lights off that we’re not using, but what about when the lights are actually on?

The best (and probably only) thing you can do is ensure you’re using lightbulbs that are as energy-efficient as possible, whether you’ve got standard or spotlight light fittings (or a mixture). In the UK, lightbulbs have commonly been of the traditional or halogen varieties, which are not efficient types of bulb. There has been a move in recent years to encourage people to move away from buying these bulbs and start purchasing more energy-efficient alternatives.

How have lightbulbs changed?

Having first been employed extensively in the late 1870s on both sides of the Atlantic, it was inevitable that lightbulbs would be improved upon. The merger of Thomas Edison and Joseph Swan’s competing companies in 1883 created the first mass lightbulb manufacturer, but the incandescent bulbs they made at the time are now largely obsolete. This is due to newer materials that were unavailable at the time, combined with newer technologies and greater understanding of the physics involved. The alternatives we have now are cheaper, brighter and longer-lasting than the bulbs that lit up buildings 140 years ago.

What energy-efficient lightbulbs are available now?

There are now two main kinds of energy-efficient lightbulb available to UK customers: Compact Fluorescent Lamps (CFLs) and Light Emitting Diodes (LEDs). 

Here are a few of their key stats compared to the halogen bulbs that have largely been phased out:

Lifespan1,000-2,000 hours8,000 hours25,000 hours
Cost per year to operate£23.88£5.07£3.60
CO2 emissions per year172.68kg44.02kg28.80kg
Initial cost£2-£6£2-£13£2-£12

Stats taken from

There are clear and obvious advantages to using CFLs or LEDs. They last longer, they cost less for you to operate and they’re better for the environment. In any rate, it is becoming increasingly difficult to get your hands on incandescent or halogen lightbulbs, as they’ve been phased out within the EU wherever possible available (though sometimes they need to be used in ovens and security lights).

Are energy-efficient lightbulbs more expensive than incandescent lightbulbs?

No - looking at the table, you’d think that energy-efficient lightbulbs are more expensive than incandescent options, this isn’t really the case. Although the top-end bulbs can cost £12 or £13 as opposed to a top-end incandescent costing £6, it’s worth remembering that, if you need to spend that much on the bulb, the savings you’ll make over its lifetime are significant. This is because the bulb will last much longer than incandescents - as you can see, it will last around 25,000 hours, which is much longer than the potential 2,000 hours an incandescent would last. If you had the bulb on for six hours a day, it would last over 4,000 days. 

Do energy-efficient lightbulbs really make a difference to the environment?

Yes, by virtue of the fact that they use less energy than incandescent bulbs. A lot of the energy that incandescent bulbs use ends up being wasted as heat rather than light, but not so much heat that you can benefit from it. Not only does a CFL or LED bulb use less energy, but a much greater proportion goes into light being emitted rather than heat.

Additionally, if they use less energy, this dramatically decreases demand from power plants and therefore lessens greenhouse gas emissions. Their longer lifespan means they won’t end up as landfill as readily as bulbs that last for significantly less time, as they can be recycled easily at a normal recycling station. Finally, in theory, fewer materials are needed to create the bulbs because fewer are needed, though this is obviously difficult to substantiate.

How can I use my energy-efficient lightbulbs...efficiently?

While investing in energy-efficient lightbulbs is a great first step, there are various ways in which you can make sure you’re using your lights efficiently when they’re on.

  • Make sure you turn the lights off when you leave the room, unless you’re coming back

  • Only turn on the lights you need - for example, you probably don’t need to have both the overhead lights and the lamps on

  • Put external lights on a timer or a motion sensor, so they’re only on when they’re needed. Your energy bill won’t be too high and your neighbours will thank you! 

Ultimately, lightbulbs are only one step towards ensuring that your life is as energy-efficient as possible - there are a huge number of things you can do to save energy in all areas of your life, as you can see here. However, when you consider the ease with which you can switch your poorly-performing lightbulbs for long-lasting, energy-efficient options and the overall effect they’ll have on your bill, this is by far the best (and quickest) place for you to start.