The cost of programs designed to save energy works out to 4.4 cents per kilowatt hour, less than half of what power from a conventional coal-burning plant costs, according to an analysis from the Lawrence Berkeley National Laboratory.

The authors of the report, released in mid-November, collected energy efficiency information from more than 100 program administrators in 34 states, covering 5,900 “program years” between 2009 and 2013. They looked at a number of residential efficiency programs, including programs that subsidize whole-house retrofits, lighting improvements, appliance swaps, and efficiency measures for electronic devices.

Overall, the authors found that the cost of saved energy (CSE) was 4.4 cents/kWh, with residential programs having the lowest cost (3 cents/ kWh); commercial, industrial and agriculture programs followed at 5.6 cents/kWh.

This compares with the 9.5 cents/kWh for producing electricity in a conventional coal plant, Merrian Burgeon writes in a blog for the Natural Resources Defense Council.

“This means that smarter uses of energy can replace dirty coal at a fraction of the cost of building coal plants to generate electricity (and without polluting our air or exacerbating climate disruption),” she says.