Now is the time to plan for the integration of significant quantities of distributed renewable energy into the electricity grid. Concerns about climate change, the adoption of state-level renewable portfolio standards and incentives, and accelerated cost reductions are driving steep growth in U.S. renewable energy technologies. This book addresses such concerns and in particular, the number of distributed solar photovoltaic (PV) installations, which is growing very rapidly. As distributed PV and other renewable energy technologies mature, they can provide a significant share of our nation's electricity demand. However, as their market share grows, concerns about potential impacts on the stability and operation of the electricity grid may create barriers to their future expansion. To facilitate more extensive adoption of renewable distributed electric generation, this book discusses the the Renewable Systems Interconnection (RSI) study, which looks at the technical and analytical challenges that must be addressed to enable high penetration levels of distributed renewable energy technologies.