One afternoon about 10 years ago, the Quaker Oats processing facility in Cedar Rapids contacted administrators at the University of Iowa. The oatmeal, granola, and cereal manufacturer generates thousands of tons of oat hulls each year, and it wanted to know if the university was interested in purchasing the waste product — significantly cheaper than coal — to use as a fuel in its campus power plant.
After spending $1 million on two years of testing and other preliminary work, U of I started processing oat hulls in 2003, combining them with coal and burning the mix as fuel. The deal with Quaker Oats has saved the school up to a half-million dollars each year, depending on the market price of coal. The institution plans to quadruple the amount of biomass it uses as a fuel by 2020, with a goal of making it 40 percent of the fuel mix.
"One of the big themes is, let's get our energy local," says Ferman Milster, principal engineer for renewables at the university's Office of Sustainability. He estimates that the university's goal of upping its local biomass purchases could return about $6 million annually to the local economy.
This change in U of I's energy infrastructure was made easier by the school's district energy system — a centralized boiler that delivers heating and cooling services to the campus. Now common on college campuses, these utilities are still found in some municipalities, often dating to the early 20th century, when towns were built around a dense urban core. It's far less common today to see towns installing the same infrastructure. Recently, however, the small town of West Union, Iowa, decided to give it a try, investing in a district energy system that will tap geothermal energy to lower heating and cooling costs for downtown businesses. The $2.5 million project is a collaborative effort, funded by grants from EPA, state government, and the U.S. Energy Department.
The University of New Hampshire's Eco-Line
Trash powers the University of New Hampshire's heating, cooling, and electricity-generation system. Rather than relying on natural gas, the school sources over 60 percent of its fuel from a landfill about 13 miles away. But while harnessing the methane-based gas emitted as trash biodegrades has helped UNH meet its sustainability goals, the move hasn't delivered a big financial payoff for the university.
"The market price for natural gas has dropped substantially," says Paul Chamberlin, associate vice president for facilities, so the savings have been less than UNH expected when the line was completed in 2009. The university utility still aims to recoup the cost of the $49 million investment within 10 years by selling renewable energy certificates through an EPA program and by charging campus buildings for their energy use.
Thanks to clean-air regulations, most landfills are already capturing landfill gas. But according to Chamberlin, that's not necessarily a useful fuel source for many municipalities. The University of New Hampshire, like many education institutions and some big business and manufacturing facilities, has a cogeneration plant: a facility that both heats water for heating and cooling buildings and also captures waste heat to generate electricity. It's a hugely efficient process that makes renewables an attractive investment. But in more sprawling suburban communities, installing such a system doesn't make much sense.