Renewable Energy

As the nation grapples with the problems of global warming, energy independence and sustainability, scientists and engineers are evaluating a number of renewable energy sources. Increased investment in these technologies and changes in government policies to encourage their use will make them more available and affordable.

Renewable energy sources include solar, wind, water and biomass. There are variations in each.

Solar – includes small-scale photovoltaics for buildings, large-scale arrays to supplement the electricity grid, and solar hot water heating. Recent innovations in solar technology include the production of flexible thin-film plastic photovoltaics that are lighter, more efficient, and cheaper than silica-based materials.

Wind – large, modern wind turbines are being placed in arrays in areas of strong sustained winds to provide electricity for the grid. Smaller turbines of various designs can be used to provide supplemental electricity for buildings.

Water – hydroelectric dams have long been the most reliable source of electricity from water. Electricity from tidal energy is in its infancy but prototypes are currently being tested.

Biomass – vegetative matter produced from solar energy by photosynthesis can be converted into biofuels and electricity by a wide range of technologies including direct combustion, gasification, pyrolysis, fermentation and anaerobic digestion. Of particular interest is the production of energy from waste organics.