Many new and ambitious energy efficiency and conservation laws are being enacted at all levels of government—and with greater financial incentives than provided previously. These innovations are intended to overcome or minimize market barriers such as principal-agent problems, information and transaction costs, high internal discount rates, and up-front capital needs that discourage cost-saving investments. Innovations such as public-private partnerships also require significant legal input and creativity for the client to reap the often remarkably large energy and cost savings. This article reviews a range of these tools, especially financial legal mechanisms, that could help significantly reduce U.S. energy consumption.