In recent years, searching for renewable energy resources has become something of a treasure hunt. A group of Penn State students spent their spring break in Costa Rica learning about one of those “treasures” -- cow manure.One of the students' main projects was to build an anaerobic digester -- or biodigester -- for a local dairy farmer.As part of an embedded Environmental Resource Management, or ERM, course, 14 students from the College of Agricultural Sciences traveled to EARTH University in Costa Rica to compare the country's approaches to ecotourism, waste management and sustainability to that of Pennsylvania.One of their main projects was building an anaerobic digester -- or biodigester -- for a local dairy farmer. Drew Paul, a senior ERM major, had never heard of a biodigester before this trip."This class informed me that we have one in State College, too," the Frackville, Pennsylvania, native said. "It is much more expensive and up-to-date, and the ones in Costa Rica are homemade."Biodigesters create methane gas from manure for farmers to use, Paul explained. This waste-management technique helps reduce pollution in water systems and landfills.The process the students used to build the biodigester fascinated Paul because they used entirely recycled materials, such as plastic bags, paint barrels, PVC pipe, plastic hosing and used rubber from old tires found on the sides of roads.“It required a lot of teamwork,” he said. “It took hours to complete.”Farmers in Costa Rica often use their biodigesters to produce methane gas for cooking on stoves."Cows are going to produce waste no matter what," said Paul. "Instead of causing harm to the environment, Costa Ricans have used it as a fertilizer on their land and to produce gas as cooking fuel. Pennsylvanians have used it to produce electricity."Paul believes the future is bright for biodigesters, even though the cost is high.
"The biodigester reduces the amount of waste -- manure -- and what is left after methane gas is produced can be used as an organic fertilizer," he said. "We hope farmers will use them because they do so many good things."