How Long Does It Take? National Environmental Policy Act Timelines and Outcomes for Clean Energy Projects

Growing demand for electricity and increased interest in affordable clean energy sources have created a rich economic opportunity for renewable energy developers in recent years. However, developers have long expressed frustration with the myriad obstacles to building new generation projects—in particular, selecting a site and securing the necessary leases and federal permits. The National Environmental Policy Act of 1969 (NEPA) establishes a process of environmental review that is compulsory for any major action, including the financing of solar and wind projects and construction of utility-scale renewable energy projects on federal lands. Utility -scale projects are projects with a capacity greater than 20 megawatts (AC), as FERC has adopted 20 megawatts as the cut-off for large merchant generators. 20 megawatt or greater capacity is considered competitive for wholesale power markets (NARUC and U.S. AID n.d.; Urban Grid 2019). Its requirements are often mentioned as a major obstacle to renewable energy development, but does the NEPA process significantly delay renewable energy projects? Would adjustments to NEPA accelerate the clean energy transition? We examine the experience for solar, wind, and geothermal power plants that completed the NEPA process from 2009 to 2023 to provide new insights into these questions. Over this period, we find that the solar and wind projects subject to NEPA review account for only a small fraction of the total utility-scale renewable capacity brought online from 2010 through 2023. These renewable projects completed the formal NEPA process in less time than the average time for all project types across all federal agencies. Almost two-thirds of these solar and wind projects did so within one to two years; however, a number of the remaining projects required substantially longer.