There are several ways of  saving energy but most of these methods demand a concerted effort and a great deal of investment. A simple, almost no-cost solution, is to minimise energy for lighting in the evenings by utilising sunlight longer.

A solution to saving sunlight suitable for India has been proposed by Professors Dilip R Ahuja, and D P Sen Gupta, of  the National Institute of Advanced Studies, and V K Agrawal , Director, Southern Regional Load Dispatch Centre, Bangalore. They propose that the Indian Standard Time be advanced by half an hour once and for all.
 Understanding what this does requires a closer look at how time is calculated. It is common knowledge that while the earth spins, the eastern parts of the earth face the sun first, so the sun rises early and also sets early in the eastern sector. 

When the sun is right overhead, the place where one is standing is facing the sun directly. Let us assume it is 12 noon. If we draw an imaginary line joining the North Pole, the South Pole and this point (where the Sun appears at that instant), all places along that line will have the sun directly above them and it will be 12 noon. This line is called a longitude.

When the sun is on the horizon appearing to set, the earth has turned 90 degrees and the time will be 6 p.m. So it took the earth 6 hours to turn 90 degrees; in 1 hour it turns 15 degrees.

Let us take the case of Imphal in the east. When it is 12 noon there, Mumbai, about 30 degrees to the west of Imphal, will be two hours behind and the clock there should show 10 in the morning, but we cannot have different times in the same country, as we move from east to west. So a standard time for a country is fixed.
Indian Standard Time(IST) was fixed considering the time at Mirzapur District (UP) on the longitude 82.5 degrees East, and  is 5 1/2 hours ahead of UTC (Universal Coordinated Time at Greenwich which is taken as reference for the world; standard times in a country are fixed with reference to this time).

 Now, if it is 6 p.m. in Mirzapur, it is considered to be 6 p.m. in the rest of the country although by then the sun has already set east of Mirzapur, at say, Imphal though it is still daylight at Mumbai.

If we shift IST 6 hours ahead of UTC, the sun might set on Mirzapur at 6.30 p.m. and in Bombay at 7.30 p.m. but both the clocks show 6 p.m., Indian Standard Time. When offices close at 6 p.m.(IST),  people in Mumbai have one and half hours more daylight and do not switch on lights at home or street lights till it is actually dark.
 In practical terms, this means commercial establishments that require power for their functioning start at the same time in terms of the clock but relative to the previous time half an hour earlier, consequently closing half an hour earlier.
Electric lights are much more widely used in the western part of the country than in the east. By delaying lighting by half an hour, sunlight is used longer.

The advocates of this proposal have calculated that around 2 billion units of electricity are saved each day by this arrangement that amounts to 600 billion units per year. Two billion out of six hundred billion? That isn’t much, but energy costs more in the evening than at other times because energy use from 6 to 9 p.m. reaches a peak and it becomes difficult to meet the demand. At Rs 6/ per unit, the saving is 12 billion rupees or 1,200 crores a year. That is not negligible.

The proposal needs to be examined by the Indian government in consultation with other stakeholders but the outlook is certainly hopeful.

(Based on the article Energy savings from advancing the Indian Standard Time by half an hour, by Dilip R. Ahuja, D P Sen Gupta and V K Agrawal in CURRENT SCIENCE, 298 VOL. 93, NO. 3, 10 AUGUST 2007 )


India plans to electrify all households by 2012, which means almost doubling the present electricity generation capacity in five years.  Almost 35 percent of the world population without access to electricity live in India. The government of India has projected a need for Rs 9 lakh crores in the 10 th and 11th Five year plans for fresh capacity additions.