The past few years have been rough for many of the administrators who oversee college and university steam plants. Prices for oil and natural gas have spiked, tumbled, and spiked again, playing havoc with budget planning at institutions that rely on those fuels to make steam—essential for heating buildings in the winter and running chillers to provide air conditioning in the summer. At colleges that burn coal to make their steam, student activists have organized marches to protest the use of a fuel that they say is not only a cause of global warming—like oil and gas—but also a source of both air pollution and, in coal-mining regions, environmental damage.
A handful of institutions, however, are quietly switching to alternative fuels for their steam plants—fuels like wood pellets or corn leaves and stalks. Known collectively as biomass, such fuels have the twin advantages of being renewable and carbon-neutral, in that burning them spews no more carbon into the atmosphere than the trees or corn plants absorbed while growing. Another big attraction is that biomass fuels can be cheaper than oil, gas, or coal—depending, of course, on where prices for traditional fuels are on a given day.
Typically, biomass fuels are waste products—the parts of trees that couldn’t be cut into straight boards at sawmills, for instance, or the parts of crops that aren’t used as food. And instead of being trucked in from a distant mine or transported from the Middle East, they’re usually found fairly close to the campuses where they’re being burned, so transportation costs are lower.
At Middlebury College, which expanded its steam plant to house a biomass boiler that came online two years ago, the savings amount to nearly $1-million a year, according to Jack Byrne, director of sustainability integration. The college estimates that it is also keeping 12,500 tons of carbon dioxide out of the atmosphere.
Middlebury has cut its use of fuel oil in half, he says. Instead of paying for oil pumped out of the ground overseas, the college is supporting the local economy by buying 20,000 tons of wood chips each year from within about 75 miles of the campus. As oil prices have increased, the estimated payback time for the $12-million project has dropped from a dozen years to eight, Mr. Byrne says.
Eastern Illinois University expects similar savings from a new $58-million steam plant it is testing this month, says Gary Reed, director of facilities planning and management. The plant, constructed by Honeywell International under a long-term contract with the university, will replace a worn-out coal plant built in the 1920s. It is expected to save enough in fuel costs to pay for itself in 20 years.
The plant has two biomass boilers that are fueled with wood chips and are capable of producing 40,000 pounds of steam per hour—either one could provide steam for the entire campus except at peak-usage levels. The facility also houses two backup boilers that can burn either oil or natural gas. Mr. Reed predicts that it will be the first solid-fuel power plant in the country to earn gold-level certification from the U.S. Green Building Council’s Leadership in Energy and Environmental Design program.
Because Illinois is a coal-producing state, the university considered “clean coal” technology, as well as natural gas. But Mr. Reed says the university’s location in an agricultural region and the uncertain futures of the coal and natural-gas industries made biomass a safer choice over the long run.
Weighing Options
Not every institution agrees. This month the University of Montana scrapped plans for a $16-million biomass plant, which officials said they could not justify when budgets are strapped and prices for natural gas are falling. The proposed plant had also been controversial because some local residents worried that it would emit more ash into their famously clear skies than would natural gas.
In January, Gov. Scott Walker of Wisconsin canceled a plan by the University of Wisconsin at Madison to build a power plant that could burn either biomass or natural gas. Mr. Walker said building a gas-only plant would save taxpayers as much as $80-million.
But the University of Missouri at Columbia, after experimenting on a modest scale with alternative fuels like chipped tires, decided that replacing one of its old coal boilers with a big biomass boiler was the best option, says Gregg Coffin, the power-plant supervisor.
The boiler, which is now under construction, is expected to go online next fall, producing 150,000 pounds of steam an hour—about a third of the 33,800-student campus’s base load. It will also generate some of the electricity the university uses.
“Every time we do a capital investment, we do a life-cycle cost analysis,” says Mr. Coffin. In this case, “biomass won out on all categories—on cost, on environmental benefit, and on benefits to the state,” which does not have other native fuel sources. (The coal the university burns is trucked in from southern Illinois.)
The boiler will start out burning wood pellets made from logging and sawmill leftovers, but Mr. Coffin says the university also plans to test corn stover—stalks and leaves—and possibly other fuels recommended by faculty members in Missouri’s agriculture programs. Switch grasses, for instance, could be grown specifically as a fuel source, and at the same time help farmers fix nutrients in the soil.
Like most of the plants burning biomass, the Eastern Illinois, Middlebury, and Missouri facilities rely on a technology called gasification. The wood chips are fed first into a low-oxygen, high-heat chamber, where they are essentially converted to a gas and some ash. The gas fuels a boiler to produce steam, which can be fed through a turbine to generate electricity before being used to heat buildings, run chillers, and meet the needs of campus labs and kitchens.
Singular Challenges
Biomass fuel technology is not new—some institutions have relied on it for years, though mostly on a smaller scale. Among longtime users are Chadron State College, Mount Wachusett Community College, and the University of Idaho.
The University of Iowa runs one of its boilers on a mix of about half Illinois coal and half oat hulls from a Quaker Oats factory in Cedar Rapids. The oat hulls cost about half as much as the coal, says Ferman Milster, associate director of utilities and energy management, and save the university $500,000 to $750,000 a year. He’s looking around for other biomass opportunities that would let the university spend its money within about 75 miles of Iowa City.
In recent years, biomass plants have also opened at Green Mountain College and the University of Minnesota at Morris. Colby College has a plant under construction.
One facility, at the University of South Carolina at Columbia, has been a notable failure. Built by Johnson Controls under a contract with the university, the $19-million plant was designed to supply 85 percent of the campus’s steam needs, with the idea being that the savings it produced would pay for its construction. But operational problems have plagued the plant, and Johnson Controls ended up reimbursing the university for the cost of continuing to use its old equipment “until we get this sorted out,” says Edward L. Walton, chief financial officer. The plant is being re-engineered.
Even when they work as designed, biomass-fueled steam plants present some challenges that traditional plants don’t. For one thing, coal, oil, and gas supply chains are well established, while finding suppliers who can provide thousands of tons of wood chips every year isn’t always easy. Middlebury, for instance, had hoped to rely on a single provider but ended up hiring a broker to deal with multiple local sources. And where the college used to get have one truckload of oil delivered every three days, the biomass boiler burns about three truckloads of chips a day during peak periods.
Storage is another issue, since biomass fuel takes up more space than coal or oil. Middlebury keeps only a two-day supply on campus but has a 20-day backup stash of tree trunks about 15 miles away, at a mill where the wood could be quickly chipped if necessary.
And increasing interest in biomass could, at some point, make the market for fuel more competitive in ways that are hard to anticipate, just as demand for ethanol has upended the corn market. Universities that have switched to biomass all say, however, that there’s plenty of fuel capacity in the market now.
Other biomass fuels are being researched—for instance, fast-growing willow shrubs, which can be harvested every three years. Middlebury has signed a contract to buy biomethane from a company that hopes to set up manure digesters on dairy farms. The contract is contingent on the company’s being able to provide the product, Mr. Byrne says, but it “gives them something to go to the bank with to get a loan.”