You would think that the fairy light tradition couldn’t come at a worst time of the year: the darkest month, when the demand for electricity surges to light our homes and run our heaters.

So, to do your bit for the environment or to keep your energy bill down, should you deny yourself this simple pleasure at home? Not according to the figures. And, after all, our brain needs light to keep us in the right frame of mind through the winter months.

How much do my fairy lights consume?

Just do the sums, based on the power indicated on the label of your fairy lights.

Indoor LED fairy lights: less than € 0.50 for 21 days

Let's take the example of 25 metres of indoor fairy lights with 360 warm white mini-LEDs. The manufacturer states power of 6 W or 0.006 kW.

• If you run your lights with a timer from 15 December to 5 January, from 4 p.m. to midnight, that's 21 d x 8 h = 168 hours.
   
• Your fairy lights consume 0.006 kWh per hour. Over the entire period, they will therefore consume 168 x 0.006 kWh = 1.008 kWh.

So no guilt trip and nothing to weigh on your year-end budget! And that's a maximum, because when the lights flash or are in light show mode, they go out and therefore consume less energy.

A string of outdoor LED lights: less than € 10

For a string of large bulbs, such as outdoor festoon lights, the power is higher, even with LED lights: with 25 lamps of 7 W each distributed over 10 m of cable, that's 175 W.

It’s still affordable, but if you put up several strings, the costs can mount very quickly. Note that there are strings of lights with a built-in photovoltaic charger, which brings consumption down to zero!

How to limit the consumption of fairy lights?

1. Opt for LED

• Buy only LED lights: they consume 7 times less electricity and are available nowadays in a wide variety of colours, with stunning effects!
• Ruthlessly dispose of old models of indoor fairy lights with incandescent micro-bulbs.
• If you have a large model of outdoor festoon lights, with small-base (E14) or large-base (E27) screw-in bulbs, replace all old incandescent or compact fluorescent bulbs with LEDs.

2. Time them to come on only when it's dark

Some fairy lights come with a built-in timer. You can also connect a single string of fairy lights to an outlet equipped with a timer.

3. Don’t go overboard

Don't give in to the temptation of going all out with 7 strings of Christmas illuminations on the pretext that LED fairy lights consume 7 times less.

4. Beware of passive consumption!

If the fairy lights are connected to a 230 V/low voltage transformer, don’t just switch off the fairy lights at any switch: unplug the transformer from the socket. 

5. Outdoor festoon lights + photovoltaic: a winning combination!

Outdoors, opt for festoon lights with a built-in photovoltaic charger: even the dim winter light will be enough to keep the lights twinkling all evening.