Conventional wisdom holds daylight-savings time reduces lighting and electricity use. Two years ago when 77 Indiana counties switched to conform, though, electricity use and costs went up. More people came home to hotter homes and used more air conditioning. All this leads to more carbon, sulfur, and mercury emissions. In addition, more evening daylight drove up driving, pollution, and health costs.
Meter readings from the 15 counties which had already adopted daylight time provided a good control group. This presents the most clear and convincing study to date showing daylight time wastes energy and money, and harms the environment and our health.