This study addresses photovoltaics (PV) distributed systems technology development; advanced distribution systems integration; system-level tests and demonstrations; technical and market analysis; resource assessment; and codes, standards, and regulatory implementation. The study defines a set of PV benefits and costs, such as greenhouse gas abatement or reliability, and then examines a series of case studies to ascertain whether the benefits of PV deployment outweigh the economic costs and how to address any shortfalls.