The proposed daylight saving (DST) time is hardly an answer to the ongoing power crisis given the fact that the government is not in a position to meet the peak-hour demand of electricity. More so, because the demand curve during peak and off-peak hours is flat.

Under the present circumstances, there would not be any energy savings as the peak demand cannot be met due to weak generation capacity. Also DST will have very little contribution in bringing down the maximum peak-time demand, experts say.

"The proposed daylight saving plan would not work here. It would have a marginal impact on load shedding or energy savings as the off- peak and peak-hour demand is almost the same now. I don't know if the management side of the programme is depending on the behavioural pattern of the masses," Dr. M. Tamim, former energy adviser and BUET professor, told The Independent yesterday.

The government is set to introduce Daylight Saving Time (DST) in the country from June next.

Tawfiq-e-Elahi Chowdhury, adviser to the Prime Minister has held two inter ministerial meetings to seek the views of senior officials on proposed DST.
Meanwhile, BERC (Bangladesh Energy Regulatory Commission) has submitted a paper on the issue to the PMO claiming that DST could save 5 per cent energy during peak hours. On the other hand, Power Cell says that it would save 21 crore unit of energy in peak hours.

"Introduction of DST will cut down on the duration of peak hours and it may have some impact on peak-hour load shedding. But it will be negligible," he said.
Dr. Rizwan Khan, vice-chancellor of the Independent University said as the demand of electricity is almost equal during day and night and the PDB (Power Development Board) supplies two thirds of the total power demand, the daylight saving plan is unlikely to yield any significant benefit.

According to a calculation, if there were adequate generation capacity to meet the demand, DST could save around 2.35 per cent of peak hour energy at the beginning of the DST since April (according to load dispatch centre). This energy saving would increase day by day and could reach 2.91 per cent on June 21. Then it will again come back to around 2.35 per cent at the end of September. The average daily gas saving would be 8-9 mmcfd. Considering the summer load curve calculated on the basis of national holiday peak shape the energy saving would be 4.89 per cent of peak hour generation of the day, a top official of PDB said. "But all things will depend on the load supply."

It may be mentioned that DST is a system that adjusts clocks forward by one hour in spring and summer and backward by one hour in autumn and winter facilitating more work in daylight and thus save electricity. The primary goal of DST is to reduce evening uses of lighting. Normally DST starts from April and ends in October.

According to historical account, British builder and outdoorman William Willett conceived and proposed DST in 1907. During World War-I, DST was introduced first in Germany on April 30, 1916. The United States adopted DST in 1918. After World War-I the practice of DST in USA was discontinued as farmers disliked it. During World War-II DST was reintroduced. The present standard form of DST in USA was introduced in 1966. A majority of countries, generally those that are closer to the equator, do not observe DST. At present in Asia only Pakistan and Iran are practicing DST.

It may be recalled that the caretaker government tried to introduce it but due to opposition from different quarters could not put it into practice.
DST's potential to save energy comes primarily from its effects on residential lighting. Delaying the nominal time of sunset and sunrise reduces the use of artificial light in the evening and increases it in the morning.

Which sector would be benefited :

Energy use in late evening may be reduced due to switching off lighting loads only (except security lights). No peak demand reduction will be observed as peak demand occurs in early evening. But energy saving or conserving benefits will occur if there is sufficient generation during evening time. With almost flat load curve, energy saving can be made forcibly. If people change their behaviour (going to bed early discarding the habit of watching satellite TV in late evening), load shedding may reduce slightly.

Only recognisable benefit of reduced load shedding will be achieved due to early shutdown of shopping malls.

Outdoor sports and evening exercise may increase due to more sunlight after working hours. Football, Hokey, Golf will be benefited but Cricket which one of the popular games in Bangladesh will not be benefited. Outdoor sports, industry and retailers may be benefited. Customers and street hawkers will be benefited from extra afternoon sunlight. Traffic fatalities during DST may decline slightly.

Which sectors would not be benefited:

Disruption may happen to meetings, overseas teleconferences, travel, billing, record keeping, medical devices, computer applications etc. due to clock change, and can be expensive.

DST clock shift twice in a year is hazardous. People must remember to change their clock. Mechanical clock cannot be moved backward easi;y. Changing time to devices containing clock is complicated and time consuming.

DST can adversely affect farmers and others whose working hours are set by the sun. For example, harvesting is best done after the dew evaporates.
As air-conditioning and fan load are increasing, extra afternoon cooling may increase household's electricity bill.

DST may increase fuel consumption in motor vehicles.

DST may have adverse effect on late evening entertainment like theater and restaurant business. DST may have adverse effect on school students' evening study as traditionally, students start evening study after sunset and thereby will have less time for study. At the same time, afternoon sunlight will not help them in urban areas to play outdoor games as there are not sufficient play grounds.
DST may disrupt sleep and may reduce efficiency for several weeks after summer transition. Study suggested increase in heart attack and suicide rate during this transition in different countries. Kazakhastan Government abolished DST in 2005 citing health complications citing clock shift as a reason.