Heating plant continues testing biomass fuel

UW-River Falls’ central heating plant exceeded the highest January bill this year—the total coming to $164,700. As fuel cost rises, the staff of the 45-year-old heating plant has made an effort to find a cheap, efficient, carbon neutral fuel. 

Wisconsin’s mean temperature in January was about seven degrees—the year before was 15 degrees, according to the National Climatic Data Center Web site. Other factors for the high bill included high enrollment and more buildings on campus to heat—like the University Center and the South Fork Suites, UWRF Heating Plant Superintendent Bill Girnau said.

Fuel cost for coal and natural gas fluctuate from year to year, but the average cost of fuel at UWRF lands around $750,000 per year. In 1987, total fuel cost in a year was $263,062.

Biomass fuel—meaning it is renewable—is an agricultural byproduct capable of being burned for heat.  The central heating plant is working with different vendors to test-fire extruded wood pellets, pucks or cubes.

Wood pellets are carbon neutral because burning wood has the same effect on the atmosphere as rotting wood.

“Carbon negative is where we really regain ecologic integrity, economic vitality and social equity,” Director of the St. Croix Institute for Sustainable Community Development Kelly Cain said in an e-mail interview.

The UWRF heating plant houses a boiler identical to ones at UW-Superior, UW-Platteville, UW-Stevens Point and UW-Whitewater. If UWRF finds a biomass fuel that can compete with coal the other campuses could make the switch without fire-testing the product. Director of Facilities Management Michael Stifter said coal-fired heating plants are ground zero for campuses when it comes to carbon neutrality goals.

“If we can find a price competitive and reliable alternative, it makes a lot of sense for us to consider it,” Stifter said in an e-mail interview. “Doing an analysis sooner, rather than later, only makes sense.”

Testing with wood pellets began about a year ago.

“We are right in the infancy of most of it,” Girnau, who began working as an operator at the heating plant in 1977 and took over in 1985 as plant chief, said.

February 2008 marked the first test-firing of wood pucks from RENEW Energy Systems. Girnau said there was limited success with the 24-ton truck load. Shaped like a hockey puck, with a 3-inch diameter, the biomass fuel did not flow well through the hopper and it broke a feeder chain. The pucks broke apart and caused burn back—combustion where it was not supposed to combust.

The next test-firing, in December, tested wood cubes from Renewafuel, LLC. The product might have worked, but something happened during the delivery.

“It was all sawdust,” Girnau said. “Twenty-three tons of this junk. They shot themselves in the foot. If product came in the way it was supposed to we would have had a more viable test-fire and been able to glean more information.”

UWRF’s current air pollution control permit allows it to combust coal, natural gas, distillate fuel oil, paper pellets and wood waste. In order to burn wood pellets consisting of 10 percent plastic content, the central heating plant received a research and testing exemption from the Department of Natural Resources (DNR).

Should the central heating plant find a biomass fuel that works efficiently, the DNR would review the project—through stack testing— and issue a permit if the project can meet all applicable rules and regulations.

The Flambeau River Mill in Park Falls, Wis., completed trials with wood pellets up to 12 percent plastic content. After completing the study in December, the facility applied for, and received a construction permit to burn the pellets regularly, according to DNR Environmental Engineering Supervisor Jeff Johnson.

UWRF is not has not reached that point. The next load of wood pellets from Bioensertech in Menomonie, Wis., will come March 25.

“If the wood pellets worked, then we could offer the students an option of paying for carbon neutral fuel,” Girnau said in an e-mail interview. “I would guess this is a couple years away due to testing and contract language and obligations.”

Field biology major Rebecca Alexander said the fire-testing is a great thing to help lessen the impact on the environment.

“In my mind, it is our responsibility to do the best that we can to reduce our impacts, save what we can, and restore what we have destructed,” Alexander said in an e-mail interview. “It’s an on-going learning process, and we need to learn from our past mistakes in order to take the action that is required in the present and the future.”