The Charlotte, N.C.-based company, which operates in the southern and central parts of Indiana, issued a statement late Friday urging Hoosiers to draw their own conclusions about the impact daylight-saving time has had on energy usage.
The study, first reported in The Wall Street Journal last week, suggested that heavier use of air conditioning last year outweighed savings in electricity directed to lights, long a staple in the argument for moving the clocks ahead.
Although Duke provided data to the researchers, the company said it does not endorse the conclusions that even the researchers admitted were "very preliminary."
After years of debate, the Indiana General Assembly approved daylight-saving time in 2005.
Duke's problems with the study include:
-It did not fully analyze the impact of weather conditions, the single biggest driver of electricity usage.
-It failed to consider that most Duke customers in the study area do not use electricity to heat their homes.
-It did not include energy data from business and industry, the sectors that consume the most electricity.
-Researchers took results from the southern part of Indiana and made broad assumptions.
Duke also pointed out that other studies contradict the one issued by University of California-Santa Barbara.