FESTIVE LIGHTING

Dear HIW,

Many houses are lit up for Christmas and other winter celebrations. How much more electricity does the world use because of this?

Chelsea Holt

The twinkling of lights is very noticeable at this time of year, but few think about the bigger impact. This was also considered by the energy company Arcadia, who worked out how much energy was being used, but also analysed the extra cost of these festive additions. With an estimate of one home using about nine strings of 100 bulbs, if these lights were on for six hours a day, 65kwh of electricity would be used throughout December for that home.

The study focused on the US, finding that 90 per cent of homes celebrated Christmas. Based on the estimate that around half of the houses in the country were lit up, 3.5 billion kwh is consumed in December. In the US alone, the cost of running these lights adds up to $645 million (£480 million).

Some people decorate their house with lights in winter