Energy Sources

            
             Among the top energy alternatives, wind and solar power have gained the most ground in popularity and effectiveness. Wind was recently rated the world's fastest-growing source of new power and its energy capacity grew at an annual rate of 25 percent to 35 percent a year over the past decade, according to the American Wind Energy Association. Part of the strategy has been in building bigger and bigger windmills that can stretch to higher levels where wind blows stronger. The giant windmills, which now reach up to 300 feet in height, also feature sprawling blades, some as long as football fields, that can generate more power. Although wind power doesn't pollute the environment, it isn't entirely harmless. The giant windmills take up vast swathes of land and their giant blades often chop down flying birds. Solar power has not advanced at the same rate as wind power, but researchers hope cutting edge technology might improve its standing as a U.S. power source in the near future. "If you can supply roof shingles or side panels that generate solar power, then solar power simply becomes part of the building cost," says Seth Dunn, an energy researcher at the World Watch Institute in Washington, D.C. Wind and solar power may be most promising, but both can't be 100 percent reliable since wind and sun turn on and off only at nature's command. Other resources promise to be more consistent. Take, for example, stores of corn, scrap wood, sawdust, pig and human waste, even dried artichokes. .
             Biomass is any animal or plant product that can be burned or fermented or concentrated for fuel. James Teaney is in charge of converting pig waste into fuel for Northwest Missouri State University. To extract power from pig waste, the sludge is dried, mixed with waste paper or sawdust and then formed into small pellets. The pellets are then burned in giant incinerators that power the campus' heating or cooling systems for one day on one and a half tons of waste.