Before it was stayed by the U.S. Supreme Court in February 2016, the Clean Power Plan offered state electric utilities and their regulators a degree of certainty as they confronted a rapidly changing market and technology landscape. Although not all agreed with the U.S. Environmental Protection Agency’s approach, the Clean Power Plan’s predictable long-term emissions reduction targets provided clear goals to evaluate investments in traditional generation sources like coal and nuclear energy and resources on the rise like natural gas, wind, solar, and distributed generation.