Half of Americans live in areas violating national health-based air quality standards. Coal- and gas-fired power plants are important contributors to the problem. The Clean Air Act has historically addressed power plants through regulation of smokestack emissions, employing “stovepiped,” pollutant-by-pollutant control strategies. Air quality has improved, but often through duplicative or conflicting requirements and at ever-increasing cost. Worse, such controls often increase CO2 emissions, consume additional water, and create thermal discharge and ash disposal concerns. This paper summarizes recent efforts to help air regulators consider energy efficiency programs as a viable alternative to smokestack controls. It outlines the regulatory challenges that must be addressed and legal constructs that can be used, and it highlights specific steps that the energy efficiency community can and should take. The paper also presents a planning tool to demonstrate to regulators how the effects of many different efficiency measures installed by many different customers can be aggregated in a sufficiently rigorous and detailed way to meet regulatory needs. Our hope is that the emissions reductions from an “Efficiency Power Plant” could be accepted by EPA and state air regulators in ways that are analogous to those from mobile sources (e.g., vehicles). The tool enables users to input as few as ~20 assumptions about the number of different “proxy” efficiency measures that will be installed, and generates seasonal and hourly emissions reduction profiles. Preliminary discussions with air regulators suggest the tool offers great promise for illustrating the impact of multiple pollutants, not only for CO2 but for criteria pollutant emissions as well.