Under Section 111(d) of the Clean Air Act, states have access to a broad palette of tools to craft an approvable, least-cost plan to comply with the U.S. Environmental Protection Agency’s (EPA) Clean Power Plan. At an Electric Utility Rate Case Seminar, Carl Linvill encouraged participants to speak like an air regulator to convey the value of energy efficiency programs. In addition to reducing emissions, energy efficiency is cost-effective, reduces risk and volatility, and provides benefits as soon as the first measures are implemented. Dr. Linvill offers a number of tools available to translate efficiency savings to tons of avoided emissions, including the energy efficiency (EE) power plant model, a mobile source analogy approach, and a variety of modeling tools. He encourages a focus on least-cost, least-risk options, including a consideration of the co-benefits such as reduced water use and multi-pollutant reductions. He also highlights the need for utility commissioners and air regulators to engage with other states, EPA regional offices, and the EPA headquarters as they develop their plans.