- Solar thermal power technology
- Wind turbines
- Biomass fuels
Critical renewable energy technologies include solar thermal power technologies, photovoltaics, wind turbines and biomass fuels. To efficiently convert solar energy into power, mirrors are used as collectors to concentrate large amounts of sunlight which is then directed at a receiver, transferred into a fluid through a transport-storage system, and finally converted into power. Efficiency losses occur in each major element of the system. The collector subsystem is the most costly element of the system. There are three primary solar thermal technologies: trough systems, dish/engine systems, and power tower systems. Research in each of the three major collector designs may reduce capital costs and increase efficiency of solar thermal power generation.
Renewable energy technologies are critical because the energy sources on which they are based can be regenerated, and they may have less of an environmental impact than conventional technologies.
Wind turbine technologies may provide an important renewable source of new electric generation capacity with lower environmental impact for U.S. and overseas markets.
Biomass fuels or biofuels are fuels made from cellulosic biomass sources that include a substantial fraction of municipal solid waste, agricultural and forestry residues, and woody and herbaceous plants grown for production of fuels. Biomass fuels can offer lower emissions than fossil fuels and are renewable.
Renewable energy technologies can serve to reduce reliance on fossil fuels, thereby increasing national energy independence and replacing polluting electricity sources. While cost is the major barrier to their commercialization, the modularity of most of these technologies promises significant cost reductions through mass production. Their impact on competitiveness of U.S. industry would be seen mostly in the ability to sell equipment based on this emerging generation technology in world markets. Cost effective energy storage (described separately) is important to most of the renewable but intermittent energy sources such as photovoltaics and wind.
Researchers in the U.S. generally believe that power towers will achieve lower energy costs and larger market impacts than trough systems. Dish/engine systems are more modular systems and are not likely to compete against either trough or power tower systems in the near term.
Europe and the United States are about even in solar thermal energy technology, slightly ahead of Japan.