Energy is blowing in the wind
Wind power is actually another form of solar energy. As the sun heats air, land and water on the surface of the earth, different areas absorb heat at different rates; the resulting temperature differentials create water and air movement , manifesting themselves as winds and ocean currents that help to keep the world running with relatively stable climate and precipitation conditions.
Wind power technologies are simply a means of taking advantage of this natural force to do useful work, rather than just watching it blow leaves around. Humankind has been making use of wind power for millennia, from the vast sailing ships of old to the large wooden windmills for grinding wheat and other grains (hence the name windmill, as opposed to simply wind turbine). The huge water pumping windmills used in Holland also made use of this natural force, to move water in the process of reclaiming land from the sea.
These methods permitted the use of wind for mechanical energy, by harnessing it into some form of physical work. The comparison to an electrical wind turbine is like the comparison of a car to a gasoline generator - one is designed to produce motion while the other is designed to produce electricity, but both use the same fuel. A wind turbine simply uses the mechanical energy captured in its spinning motion to produce electricity, for charging a battery or powering an electrical device directly.
The largest wind turbines are designed to be self-contained power plants, outputting electricity directly to the utility grid just like large coal, hydro or nuclear power plants. In some cases, these wind machines are grouped together in 'wind farms' with a nearby power substation to handle the electricity pumped out by the machines. Wind power is the single fastest growing energy source worldwide, although it currently comprises a very small portion of global energy supply - 0.051% as of 2003 according to the International Energy Association, but with growth rates of over 50% per year since then.
Small scale wind energy is an extremely viable option for year-round homes where there is a nominal level of wind - generally, this means annual average wind speeds of at least 12 miles per hour. The reason that wind will make the most sense in such abodes is because the annual availability of solar radiation complements that of wind; in the summer, there is much sun and little wind, while in the winter wind picks up and sun drops off.