Don’t tinker with the clock to save energy

On 23 March 2011, all clocks in the UK were turned forward by an hour marking the start of Daylight Saving Time (DST). The clocks will be turned back on 30 October 2011. The objective is to save energy by educing the use of artificial light and maximizing the use of daylight over a period of seven months.

While this has been the practice for many years in countries situated in the upper part of the northern hemisphere and the lower part of the southern hemisphere, DST is hardly practised in countries situated closer to the equator.

Several studies have also been conducted in India, over the last three decades, to evaluate various time-based measures for energy conservation. These include introduction of Daylight Saving Time (DST), and shifting Indian Standard Time (IST)—currently GMT + 5½ hours. In 1988, TERI undertook a detailed study for the Government of India’s Advisory Board on Energy to explore these options. The results revealed only nominal savings potential, both in terms of energy and reduction in peak load. However, it was also pointed out that the potential impacts of deploying these options need to be evaluated periodically, because as demand grows, prices change and consumption patterns vary. Therefore, TERI recently undertook a fresh study to re-examine the various issues in greater detail and came to similar conclusions, which are explained in this policy brief. However, knowledge of basic geography as regards the rotation of the earth around the sun and the impact it has on the seasons and on the varying lengths of days and nights is important for a proper understanding of the subject.