- Sep 5, 2022
- 5 min read

LEDs are definitely savvy...and why candles definitely aren't!

The headlines

A traditional incandescent or halogen bulb will burn up to £34 in its lifetime and I recommend you ditch them ALL now, including spares in the cupboard.

LEDs use a tiny fraction in comparison typically costing only around 1p to run 4 hours.

Candles are a really expensive alternative.

Here you will find clear information on the costs of different types of bulbs, common misunderstandings explained, and some tips.

This is one area of home energy efficiency where many people feel they have clear knowledge. Lighting is visible and controllable, and specialist help isn't usually needed to make changes to reduce costs. Lighting accounts for between 5% and 11% of the typical UK household energy bill. With the average bill rising to £2500 from October 2022, this means that up to £250 is being spent just on keeping the lights on.

Minimising the costs of lighting is easy, inexpensive and very worthwhile. As well as turning off unnecessary lighting, moving to lower energy lighting alternatives brings significant results.

Traditional bulb types

The panel below shows the running costs for a standard traditional incandescent 60-Watt light bulb, compared to more efficient alternatives. These costings are based on a bulb being used 4 hours daily for a year.

As you can see, LED bulb running costs are a tenth of the traditional bulb, so a house that is fully converted to LED lighting uses very little energy. LED bulbs are now widely available, bright, and very reliable. LED light bulbs typically just over 1 penny to run for just 4 hours.

Strip fluorescent tubes

Strip fluorescent tube lighting is still used in some homes, typically in kitchens and utility rooms. A single fluorescent tube is typically around 60 Watts, so running costs will be similar to the bulbs above for each strip. LED alternatives exist to replace fluorescent tubes, too.

Halogen spotlights

The panel below shows a comparison of the other very common type of bulb in the home, the halogen spotlight. These are particularly expensive to run, as homes usually have multiple sets of this type of bulb in the same room.

As you can see below, LED bulbs are again incredibly cheap to run compared to the traditional halogen spot bulb. The costs shown here are just for a single bulb, so for a room with multiple spotlights, total running costs can soon add up to very large amounts.

Clusters of halogen downlighters are very common in areas that are lit for long periods, such as kitchens, so I want to stress their high running costs:

A 50 Watt halogen light bulb will burn through around £34 in electricity during its life (around 16 months if lit for 4 hours every day).
An equivalent 5 Watt LED bulb will only cost around £1.70 to run over the same period.

There are good LED replacement spotlights now for ALL sizes of halogen bulbs, even ones in extractor hoods (see later) and they are all now very reliable with good light quality.

Common misunderstandings

There are two types of halogen spotlight bulbs. One type runs directly off mains electricity. The other runs at low voltages and is powered by a dedicated transformer unit which is usually hidden in the floor or roof space nearby. A common misunderstanding is that low-voltage spotlight bulbs use less energy than high voltage bulbs. THEY DO NOT! A 50 Watt bulb, designed to run off mains electricity, will use exactly the same amount of energy as a 50 Watt bulb designed to run off low voltage!
In the past, some people (including me!) have had poor experiences with LED bulbs: they were either a horrible colour, not as bright as they expected, or didn't last very long. They have come a long way though, as this very good video by Energy Myths explains in four minutes.
Some people are hesitant to buy LED light bulbs as they don’t believe they can be as bright as traditional bulbs. This was certainly the case with early bulbs. However, the technology has improved dramatically, and LED bulbs are now astonishingly bright.

Practical tips

If you are unsure what types of bulbs you have, an easy clue is how hot they get. Conventional incandescent bulbs and halogen bulbs of all types get VERY hot: you physically can’t touch them without risking burning yourself. It is because they generate (and waste) so much heat that they use so much energy and cost so much to run. LED bulbs get warm, but nowhere near as hot as incandescent and halogen bulbs.
Don’t wait for a traditional incandescent or halogen bulb to fail before replacing it with an LED bulb. It is much cheaper in the long run to bin all your traditional bulbs and replace them with LED bulbs at the earliest opportunity. Bin spares too!
An LED bulb will always say 'LED' somewhere on it!
Most LED bulbs now quote the amount of light output they give in 'lumens'. An LED bulb that has a light output of 850 lumens or more is about as bright as a traditional 60 Watt light bulb.
Use light rather than dark lamp shades: this will mean you can use lower power bulbs, or fewer lights, in a room.
LED bulbs can be bought with a variety of shades of white (warm white through to cool white), so you can choose different bulbs for different rooms or applications in the home.

Smart bulbs

There is a wide range of smart bulbs on the market now, that can link to phones, WiFi etc. These only have a limited ability to actually save you energy. Their main advantage is that they can be controlled remotely and do clever things, such as make the house look occupied when you out, or change colour. They actually use a small amount of power just to keep them powered up, though it won’t be much.

Outside security lights

These are typically high-power bulbs, but if they are only on for occasional short durations (such as when triggered by a sensor), the energy they consume in a year will be minimal. It IS possible to buy LED versions of security light bulbs, which can be changed without the need for a qualified electrician.

Cooker extractor hoods

These bulbs are almost always halogen. If they are regularly used for long periods, then I recommend replacing their bulbs with LED alternatives. These bulbs are unusual and quite varied (usually a type called G4). Good quality LED alternatives are only around £3 from places like Toolstation and electrical supplies shops.

Candles

It might be tempting to think that using candles will be a lower cost way of lighting a room. You can buy fifty 8-hour tea candles for around £8 online, so 16p per candle.

An 8-hour tea candle will cost 2p an hour to run. This compares to an LED light bulb at just 0.2 pence.

Of course, candles do provide SOME heat, so could this mean they are actually sensible to use for both light and heat? The answer is NO! They are actually the most expensive way to keep warm. See my other article about using candles for heating and why they are not a savvy idea for that either.

The assumptions above are all based on a 5W LED bulb and the 34p electricity rate from October 22.

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Thanks.

Mark Thompson

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