Xmas light energy consumption costs - facts to help you enjoy Xmas more
The headlines
The good news, is that mains powered LED Xmas lights and decorations don't cost much to run at all, usually running for many hours for just a penny of electricity. This is especially true for newer LED based ones.
Xmas lights or decorations using disposable batteries are MUCH more expensive to run. For AA battery powered lights I've looked at, and based on their published technical product information, their running costs are around two hundreds times the running costs of similar products powered on mains electricity.
Some Xmas decorations can be powered using either battery power OR mains electricity. Running these off mains electricity rather than batteries will always be far cheaper.
Below are some examples from Xmas lights I've recently measured or researched with approximate running costs, and estimates for battery life for battery powered ones.
Examples or running costs for mains powered Xmas lights
This tree has recently purchased LED Xmas tree lights with 300 LEDs. Amazingly, this runs for around 10 hours on a penny of electricity. That is even cheaper to run than a typical ordinary LED light bulb.
This Argos "neon" tree also costs around a penny to run for 10 hours
This Argos neon reindeer is a little more expensive. A penny of energy will run this for around 5 hours.
This Illuminated santa ladder from Amazon. You can keep Santa happy and lit on his ladder for four hours on a penny of electricity.
Battery powered Xmas decorations
Battery powered decorations may seem more convenient than mains powered decorations and much safer for outdoor use. They do though work out much MUCH more expensive to run.
The figures below all assume that the lights were on full brightness, and not flashing, and so are the worst case figures.
Calculating the running costs of these is a little tricky. But from my sums this 34cm high illuminated snowman from from Argos would cost a maximum around 11 pence an hour to run in battery costs.
The batteries may need replacing as often as every 6 or 7 hours of operation.
This 100 LED battery powered set of Xmas lights from Amazon would cost up to around 17p an hour to run when, and the batteries may need changing as often as every 4 or 5 hours.
This battery powered star decoration is from Amazon. I don't have good technical information on this product so can only estimate that this could cost as much as around 3 pence an hour using disposable batteries, and the batteries may need replacing every 24 hours or so of use.
Since posting this blog I've had some messages from people that their battery powered Xmas lights last a lot longer than the figures above suggest. This could either be because the manufacturers are very cautious (or inaccurate) with the technical information they provide online I've used, or that people aren't operating the lights at full/constant brightness, or a combination of both. Either way, using battery powered Xmas lights will still be something like 200 times more expensive than a mains powered products used in the same way.
Using batteries is also obviously undesirable also because they use toxic chemicals which can get into the environment if they aren't properly recycled.
Cutting the running costs of battery products by using rechargeable batteries
Using rechargeable batteries (such as rechargeable AA and AAA batteries) or products that have their own internal rechargeable battery will work out a lot cheaper than disposables.
Using rechargeable batteries or products would slash running costs, to perhaps 2-3 times as costly as using mains powered products.
Tip: If you do decide to switch to using rechargeable batteries (such as AA and AAA) for whatever uses you may have in a home, I highly recommend you buy really good brand rechargeables and don't skimp on the charger. You'll get much better battery performance and life.
Older LED lights
If your LEDs lights are quite old (say ten years or more) from my experience they will probably use more than those above. I've only managed to test one set of older LED Xmas lights. They surprised me costing around a penny an hour to run, around ten times the amount of modern products.
If your LED lights have a "lumpy brick" power adapters like this that gets quite warm then this probably means your LED lights are of this older type. Modern LEDs have much smaller, more efficient power adapters.
Xmas tree lights using conventional incandescent light bulbs (i.e. NOT LEDs)
These are likely to be very rare now, but if you have Xmas tree lights such as those in the photo below the running costs of these will be much higher than the latest LED Xmas lights.
A set of Xmas tree lights with 100 of these bulbs will cost a little over a penny an hour to run, approximately 10 times the cost of modern LED Xmas tree lights.
If you are unsure if your Xmas lights are LED or the older incandescent bulbs if the bulb surfaces get hot very hot (usually too hot to touch) then they are the older incandescent type.
Can you add to the above information?
Are you someone measured the energy consumption of your Xmas lights or decorations? If so do let me know what results you have had and ping a photo through and I'll add your information to the above article.
Geeky assumptions behind the above calculations
All figures above are based on electricity unit rates of 28p/kWh, as of December 2023 using manufacturers published information where possible.
Battery capacity assumed is 4.4Wh for a AA battery.
Battery costs assume using Asda basics bulk buy 50 pack, working out at 24p per battery.
Costs all assume constant illumination of the decorations (i.e. not flashing)
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Thanks
Mark Thompson
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