As states prepare plans to comply with the United States Environmental Protection Agency’s (EPA) proposed Clean Power Plan (CPP), regulators must choose from an unusually broad palette of options to reduce carbon emissions. The EPA has not only established four main building blocks to determine individual state emissions reduction targets—energy efficiency, heat rate improvements, re-dispatch to natural gas, and non-emitting generation like renewable energy and nuclear power— it encourages states to also think beyond these four measures. In a presentation at the University of Pennsylvania’s Kleinman Center for Energy Policy, Dave Farnsworth provided insight into other compliance options, their relevance, and why a CPP compliance plan is not a typical state implementation plan (SIP). The Clean Air Act (CAA) requires EPA to establish a “best system of emission reduction,” taking into account cost, remaining useful life, and non-air benefits. As a result, the agency developed the four building blocks approach to provide a consistent, legally-defensible way to determine state specific emissions targets. Yet these options are not intended to restrict regulators to those options alone. States have much more leeway, as compared with SIPs, to submit alternative or innovative strategies for achieving the required emissions reductions that are tailored to their specific needs. In addition to exploring the benefits of regional approaches or integrated multi-pollutant programs, states might choose to employ other methods, such as adopting cap-and-invest programs, optimizing grid operations, reducing losses in the transmission and distribution system, or fostering new markets for energy efficiency.