This paper provides a framework for companies seeking to demonstrate leadership in the transition towards a clean energy economy powered by 100% renewable electricity. It draws on best practice already being implemented by leading companies working to source 100% renewable electricity as part of RE100, an initiative led by The Climate Group in partnership with CDP. There are multiple ways in which a company can demonstrate leadership on renewable electricity. For each of these dimensions, a case study is provided to illustrate how RE100 members are accelerating market shifts.