Northwest Power and Conservation Council, Jan. 3, 2017, by Tina Jayaweera.
http://www.nwcouncil.org/news/blog/ee-baseline/

 "Since 1978, the Pacific Northwest has successfully saved 6,000 average megawatts of electricity, and energy efficiency is now our second largest resource after hydropower. But, how do we know it’s grown that much? To begin with, to measure growth, you have to start with a fixed point. For the Northwest Power and Conservation Council, when we estimate the energy-efficiency potential for the region, we use a “frozen efficiency baseline” as our starting point. And the baseline is based on the efficiency of products available today."