This is an edited version of a conversation with Clack on Oct. 25, 2016.
Harrison Dreves: Could you summarize the findings the paper you co-authored in Nature Climate Change?
Chris Clack: In really simple terms, the lowest cost electricity option for the U.S., with today's technology, is 80 percent carbon free generation. A lot of people that read the paper assume we wanted 80 percent renewables. We actually asked 'what is the lowest cost system?' and then what falls out from that is a national transmission system with lower cost electricity.