Which energy saving bulbs should you buy?
Buy LED bulbs. The Energy Saving Trust says LEDs are the most energy efficient bulbs you can get, and that you will now only really see LEDs in shops. Other types have been phased out or are on their way out.
That makes choosing energy saving bulbs simpler than it used to be. The real decisions are brightness, colour and whether you need to dim them. Get those right and the bulb does its job for years.
Lighting is only a small part of the average UK household energy bill, according to the Energy Saving Trust, so do not expect energy saving bulbs to transform your costs. They are one of the cheapest and easiest upgrades you can do yourself, which is why they are worth ten minutes this autumn.
Clocks have just gone back, so the lights are on for longer. It is a fair moment to look at which energy saving bulbs, if any, are actually in your ceiling.
How much can energy saving bulbs save?
The Energy Saving Trust says that replacing the halogen spotlights you still have with LEDs could save around £45 a year in Great Britain. Its page says LEDs are as powerful as halogen bulbs but use 80% less electricity, and can last up to 20 times longer.
Treat £45 as an upper guide, not a promise. It depends on how many halogens you still have, how long the lights are on and what you pay per unit. If you have already swapped most of your bulbs, your saving will be smaller.
The same source says switching lights off when you leave a room could save around £7 a year. Small numbers, but they cost nothing to try.
Older bulbs are the real culprits. The Energy Saving Trust says only about 5% of the electricity an old incandescent bulb uses becomes visible light. It also says the sale of incandescent bulbs was banned in 2021, but you may still find a few in a spare room or a cupboard.
Key takeaways on energy saving bulbs
- LEDs are the most efficient type, and the only type you will mostly see on shelves.
- Swapping remaining halogen spotlights could save around £45 a year in Great Britain, according to the Energy Saving Trust.
- Switching lights off when you leave a room could save around £7 a year.
- Smart bulbs are not likely to save energy, says the Energy Saving Trust.
How do you choose the right energy saving bulbs?
Look at lumens, not watts, when you compare energy saving bulbs. Watts tell you how much power a bulb uses, and lumens tell you how bright it is. The Energy Saving Trust gives approximate LED equivalents for old incandescent bulbs, so you can match brightness without guessing.
A 40 watt bulb is roughly 470 lumens, a 60 watt bulb is roughly 800 lumens, a 75 watt bulb is roughly 1,050 lumens and a 100 watt bulb is roughly 1,520 lumens. If you buy a bulb with too few lumens, it will feel dim and you will blame the bulb.
Next, pick a colour. LEDs used to have a reputation for harsh white light, but you can now get a range of tones. The Energy Saving Trust describes very warm white at around 2700K, which tends to suit living areas and bedrooms, and warm white at 2700 to 3000K for most general lighting.
Cool white, at 4000 to 4500K, is a purer white that can feel harsh in many rooms. It may suit bathrooms and maybe kitchens. If you see a colour rendering index, or CRI, a score of 80 or more is good for most household tasks.
Do energy saving bulbs work with dimmers?
Only if they are labelled as dimmable. Not all LED bulbs work with a dimmer switch, so check the packaging before you buy. The Energy Saving Trust warns that if your dimmer was not designed for LEDs, it probably will not work properly.
In that case you may need an LED compatible dimmer, and the Energy Saving Trust suggests speaking to an electrician to make sure it is fully compatible with your lights. Do not fiddle with wiring yourself if you are not sure.
Some fittings can be replaced with integrated LED versions, such as downlighters, strip lights and outdoor lights. That job needs an electrician, but it can give you more brightness than a normal LED bulb of the same wattage. Integrated LED downlighters are often fire rated, which the Energy Saving Trust says should make them safer in a fire than a fitting with a separate bulb.
What else cuts your lighting bill?
Use lamps or smaller lights for parts of a room, so you do not need the big light on for everything. Use sensors or timers on outdoor lights so they are only on when you need them.
Be careful with smart bulbs. They give you more control and more colours, but the Energy Saving Trust says they are not likely to save energy.
Lighting is the small fix. Your energy tariff is the big one. If you have not looked at your energy deal for a while, that is the Do Nothing Default doing its work. Our guide to choosing an energy tariff is a good next read, and our post on standby power costs covers another quiet drain on your bill.
If your home is cold as well as dim, our guide to the cost of running an electric heater shows how to work out the sums.
Frequently asked questions about energy saving bulbs
- Are LED bulbs the best energy saving bulbs?
- The Energy Saving Trust says LEDs are by far the most energy efficient type of bulb, and it recommends switching to LEDs in almost every situation.
- Can I still buy halogen or incandescent bulbs?
- The Energy Saving Trust says incandescent bulb sales were banned in 2021 and that other older types are being phased out. You may still have some at home.
- How much do energy saving bulbs save a year?
- The Energy Saving Trust says replacing remaining halogen spotlights with LEDs could save around £45 a year in Great Britain. Your own saving depends on your bulbs and how long they are on.
- What does lumen mean on a light bulb?
- Lumens measure how bright a bulb is. Watts measure how much power it uses. Check the lumen value when you buy.
- Do smart bulbs save energy?
- The Energy Saving Trust says smart bulbs are not likely to save energy, although they offer more control and colours.
