While there has been interest in promoting the use of renewable energy in electricity production for a number of years in the United States, the market share of non-hydro renewable energy sources in electricity production has remained at about 2 percent over the past decade. The paper reviews the principal energy resources used for electricity production, considers the changing regulatory environment for the electricity industry, and describes government policies that have been used to promote green electricity in the United States, with an emphasis on measures adopted by state governments. Factors influencing the development of green power markets are also discussed, including underlying economic issues, public policy measures, the regulatory environment, external costs, and subsidies. Without significant increases in fossil fuel prices, much more stringent environmental regulations, or significant changes in electricity customer preferences, green electricity markets are likely to develop slowly in the United States. (c) 2004 Elsevier Ltd. All rights reserved.