Wind Power Is One Of Several Renewable Energy Options

Wind power is one of several renewable energy options. Other renewable sources include sunlight (photovoltaics), heat from the sun (solar thermal), naturally occurring underground steam and heat (geothermal), plant and animal waste (biomass), and water (hydropower). Unlike fossil fuels,6 renewable energy sources are continuously replenished.

Wind turbines can be used by themselves or be connected to a utility power grid. Stand-alone turbines can be used for pumping water-for example, to irrigate fields. However, homeowners and farmers in windy areas can also use stand-alone turbines to generate electricity for their own personal or on-farm use. For utility-scale sources of wind power, a number of turbines are usually built close together to form a wind farm. Currently, more than 50 electric power utilities use wind farms to produce part of the electricity supplied to their customers.

In general, wind turbines are divided into two major categories: horizontal axis turbines, which resemble a windmill, and vertical axis turbines, which resemble an eggbeater. Figure 2 depicts each type of turbine.