Earlier DST Has Had Minimal Energy Effect
Having Daylight Saving Time start a month earlier than normal was supposed to help conserve energy, but early indications are that the change did not make much of a difference. However, the writing may have already been on the wall as a study by the Energy Department last year indicated that the energy savings would be minimal. A survey of major utilities recently seemed to confirm that original belief.
The reason why could be the colder spring in much of the country; as we awaken earlier, we use more energy due to the need to light and warm the house. On average, heating and cooling of one's house uses far more energy than lighting. Congress plans to evaluate the effect of the earlier switch as more data becomes available. For now, the biggest effect appears to be on the electronics that needed to be updated to reflect the change.