This report describes the study findings, which are based on interviews and discussions with the nation's six established ISO/RTOs – the California ISO, the New York ISO, the Midwest ISO, ISO New England, the Electric Reliability Council of Texas, and the PJM Interconnection. In addition, this report summarizes information on bottlenecks gathered from other sources, including the Federal Energy Regulatory Commission, the Western Governors' Association, the North American Electric Reliability Council, and the Edison Electric Institute.