Fuel for Thought

Manure is not the only farm by-product Penn State scientists have identified as holding energy that can be released and used, and biomass is not the only renewable, sustainable energy source being investigated.

• Agricultural engineer Dennis Buffington has compared the energy value and cost of burning shelled corn to that of other energy sources. He’s found that when the prices of conventional fuels are high, it could pay to burn corn as a heat source for homes or other buildings.

Burning corn in a specially designed stove has several benefits, according to Buffington. “It’s much, much cleaner than coal or wood— in fact, it’s probably about as clean as burning natural gas or propane,” he says. “We can get a replenished supply of corn every year, compared to the hundreds of millions of years it takes for the fossil fuels.”

Buffington has developed a Web site where people can learn more about burning shelled corn and compare the cost of corn to that of other fuels. The site can be found at http://energy.cas.psu.edu/burncorn/shellcorn.html.

• Agricultural engineer Jim Garthe began working in 1993 to convert nonrecyclable agricultural waste plastic into a cleanburning energy source. Just over a decade later, with funding from the Pennsylvania Department of Agriculture and the American Plastics Council, Garthe’s team completed construction of a machine that converts 500 pounds of plastic per hour into fuel pellets. Using a specially designed burner, these pellets burn cleanly at well below EPA toxic-emissions standards.

Garthe this year is taking the machine, housed in a mobile trailer, on the road for a demo tour. He hopes to see the technology commercialized and then expanded beyond agricultural use, so that all nonrecyclable waste plastics eventually can be used for energy.

“Our mission is to alleviate the burgeoning problem of waste plastics in our environment,” says Garthe. “We want to get energy from waste products, and plastics have energy we can recover. Properly done, plastic can supplement coal in coal-fired boilers. Why should we continue to throw energy into landfills?”

• In an effort to promote and demonstrate the use of green energy, Penn State Cooperative Extension’s Westmoreland County office, led by Gary Sheppard, operates a hybrid solar and wind power facility. The electricity-generating system serves to educate the community about alternative power sources and renewable energy credits—financial incentives for individuals and businesses to invest in renewable energy development.

This concept is gaining ground in Pennsylvania since the Renewable Standards Portfolio Act was passed in 2005. The act requires that by 2020, 18 percent of electricity sold in the state must come from a renewable source.

“This system offers a source of green power along with considerable cost savings to cooperative extension and the county,” says Sheppard. “The facility also is being used to develop educational programs for farmers and rural residents throughout the region. The wind turbine and solar photovoltaic array is estimated to produce 21,014 kilowatt-hours of electricity annually. Over a 25-year period, the hybrid system should produce 525,350 kilowatt-hours of electricity. At the current average cost of a kilowatt-hour, the system should produce more than $45,000 in revenue and avoided costs.”

—Jeff Mulhollem