Massachusetts has long been a national leader in efforts to capture clean energy economic development opportunities, enhance energy security, and reduce emissions. The state’s Renewable Portfolio Standard (RPS) legislation is an important part of this leadership in combatting climate change. RPS policies are the foundation for clean energy markets and a proven policy tool to support successful, cost-effective renewable energy development at the state level. An RPS is a market-based mechanism that creates demand for clean energy, which can be met by a variety of cost-effective resources.