Wind

=Wind Energy = Wind has long been used as a source of energy; initially in propelling boats, although the idea of using wind power to produce electricity dates back to the 1880s. The wind is actually a type of solar energy; winds are created by the uneven heating of the atmosphere by the Sun, the irregularities of the Earth's surface, and the rotation of the Earth. Wind energy is captured by turbines, which convert wind's kinetic energy into mechanical power that is then converted to electricity by a generator. As the wind turns the turbine blades, a shaft connected to a generator spins, producing electricity. Wind power in the United States is a growing industry. According to the American Wind Energy Association, as of January of 2008, wind provided more than 16,800MW of installed capacity in the U.S., just over one percent of the total electricity supply. The goal is to increase that amount to five percent by 2020. The primary advantage of wind power is that it is a clean fuel source that relies on the renewable power of the wind. Further, with a price range between four and six cents per kilowatt hour, wind power is one of the lowest-priced renewable energy technologies currently available. Even those prices are expected to decrease further upon the continued advancement of turbine technology. Despite its cost effectiveness relative to other renewable energy alternatives, the initial costs of building and installing wind farms are still more expensive than that of fossil fuel generators, hindering its ability to compete with lower cost conventional energy sources, including coal and natural gas. A continuing challenge is that wind energy is a source of intermittent power; if the wind doesn't blow, there is no power. Moreover, the use of wind power is under constant debate regarding concerns about consistency, noise, visual effects, and potential effects on wildlife, particularly birds.   U.S. Department of Energy: Wind Energy Technologies Program

The Office of Energy Efficiency and Renewable Energy's website for wind energy provides the basics, including how wind turbines work, the advantages and disadvantages of the technology, and current research and development. The site also includes a wind turbine animation, demonstrating how a wind turbine works.  American Wind Energy Association (AWEA)

The AWEA is a national trade association that represents the wind industry. Their site contains a variety of resources on wind energy, including news, policy and regulations, fact sheets, and a resource library.  Assessing the Life Cycle of Wind Turbine Production

This article on RenewableEnergyAccess.com discusses utilizing life cycle analysis to determine total greenhouse gas emissions of wind turbine production in Denmark. []