As recommended by the previous Academy report by the Committee on Optical Science and Engineering, enhancing the efficiency and efficacy of new lighting sources and delivery systems to realize broad-based societal benefits will require a cooperative, cost-shared approach to public-private R&D support. This report of a workshop builds on this previous analysis and highlights a variety of specific technical, infrastructure, and marketing challenges that many experts believe must be overcome before the economic and social benefits of solid-state lighting can be realized.