Increasing electricity demand is accompanied by concerns about the availability and price of fossil fuels and about the environmental impacts of electric power generation. Emerging non-nuclear energy technologies and systems can offer several potential advantages to complement conventional sources of energy to meet future needs. The advantages of the alternative technologies, however, must be balanced against the inherent limitations associated with some of the technologies. The technologies using alternative energy sources have been under active development for the past decade, and require continued technology development to improve performance, economics, reliability, and environmental acceptability. The technologies closest to, or having reached, small-scale production status include small wind systems, dry-steam geothermal, and biomass processes. Fuel cells, grid-connected photovoltaics, solar thermal, water-dominated geothermal, advanced coal systems, and energy storage systems require more development before they can contribute effectively. The American Nuclear Society recognizes that many renewable and emerging energy technology systems can contribute to the overall reliability of the electric grid. That contribution is limited, however, by the location-specific nature of many sources and requires major technological development.