In collaboration with the Tennessee Valley Authority Southern Company, the Sacramento Municipal Utility District, the California Independent System Operator, and other partners, Electric Power Research Institute (EPRI) will develop high-penetration solar future scenarios in the southeastern U.S., distribution grid-feeder clustering and characterization, models for solar generation hosting capacity, and power production simulation. These tools, processes, and studies will be used to assess the full breadth of operational and business impacts posed by high levels of solar generation and to formulate associated strategic plans for the southeastern U.S. that ensure both system reliability and utility financial health.