Harold Lloyd in "Safety First" (public domain image)
Harold Lloyd in “Safety First” (public domain image)

It’s an old joke – If we have more daylight then we have more sunshine so, naturally, the world will get warmer.

It seems obvious that, in reality, daylight saving will reduce our need for lighting and, therefore, our electricity consumption. So obvious, in fact, that until now it seems that nobody had bothered to test it. Now a study by the University of California Energy Institute has thrown new light on the subject.

The study examined the electricity consumption residents of southern Indiana over a period of three years by analysing some seven million monthly electricity bills.

The result: daylight savings actually increases electricity demand, instead of lessening it!

Daylight saving caused electrical demand to rise almost 1 percent each year overall – with the heaviest increase of 2-4 percent in the autumn. The cause is most likely a tradeoff between the reduced demand for lighting and a relatively small increased demand for heating and cooling. But, because heating and cooling uses much more electricity than lighting, the net effect was an overall increase in electricity consumption.

The study points out that daylight saving is practiced in 76 countries and affects around 1.6 billion people. If it really is causing needless energy consumption, stopping daylight saving could reduce greenhouse gas production and help reduce global warming.