A win-win: School gets energy-efficient wood heating, DNR pilots bioenergy in a public building

Northport School District Superintendent Don Baribault had an expensive problem on his hands: An old diesel boiler in the preschool-through-eighth-grade building on the Northport Elementary/Middle/High School campus was failing. It needed constant maintenance, but the district didn’t have the budget to upgrade its heating system.

Then the district received a call from the Washington State University Energy Program, inquiring if the district had an interest in some grant money to install wood energy at the school through a state-funded bioenergy pilot program. It would be the first time the state installed a wood pellet boiler for a public building.

“It was not only greener, but it was a long-term cost savings,” Baribault said. The school district agreed to the project, and after a couple years of planning, crews installed the boiler this week.

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The 340 MBH biomass boiler in Northport is expected to use about 70 tons of wood pellets, displacing about 8,500 gallons of fuel oil per year. (Wisewood Energy photo)

The campus serves about 200 students, and Baribault said they have all enjoyed watching the project unfold.

The boiler system was installed in a shipping container and placed alongside a 24-foot-tall silo that can hold 30 tons of wood pellets. As crews used a crane to install the system, some of the younger kids at recess asked if they were getting a spaceship, Baribault said. Older students and the staff appreciate that they are getting a heating system that is more energy efficient and better for the environment.

“To be able to do that on a grant was pretty cool,” he said.

The boiler is heating two buildings on the campus: the building for preschool through eighth grade, and the building that houses the gymnasium and cafeteria. In addition to installing the biomass system, the project also included integrating the heating systems for the two buildings.

Energy efficient, low carbon

Using wood pellets or wood chips to displace oil for heating is one of the best, low carbon examples of modern wood energy. These wood fuels are made from the byproducts of timber or forest restoration activities, and when used in a highly efficient system such as Northport’s new boiler, the amount of carbon emitted during combustion is recaptured by tree growth in a short period of time, if not immediately.

At Northport, the boiler requires 70 tons of wood pellets a year, and it has an estimated 85 percent efficiency rating, meaning 15 percent of the energy burned is lost while the remaining 85 percent becomes heat.

The new heating system is expected to save the school district approximately $10,000 a year – and even more if the price of oil rises, according to Wisewood Energy, the Portland-based biomass energy developer that led the project’s construction and final design.

Here’s how the 340 MBH (100 kW) boiler works:

  • Pellets are conveyed from the nearby silo to the boiler as needed, where they are burned to heat water.
  • The hot water travels to three thermal storage tanks, which combined can hold 1,085 gallons of water.
  • The system dispatches hot water from the tanks as needed to heat the buildings.
  • As hot water leaves the thermal tanks, it passes through an oil boiler in the gym, which was retained to serve as a backup and supplemental heat source for the wood pellet boiler.
  • If the backup boiler senses that the water coming from the thermal storage tanks is too cold, it will kick in to assist.

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“The biomass boiler was sized to be able to provide approximately 95 percent of the school’s heat demand,” said Meagan Hartman of Wisewood Energy. “The gymnasium’s existing oil boiler will provide the remaining 5 percent, which will occur during peak demand and shoulder seasons.”

Building and installing the new boiler, and integrating it into the backup system, cost about $400,000, Nuss said.

Wood chip heating in Forks

The Northport project is the first time Washington state has funded the installation of a wood pellet boiler to heat a public facility, but it’s not the first biomass energy project supported by the Washington State Wood Energy Team.

In 2010, the Quillayute Valley School District installed a biomass boiler at Forks Middle School and Forks High School that runs on wood chips rather than pellets. Funding for the $2.6 million project (which included a new building and a heating and cooling system), was provided by a $1 million state grant and a $1.6 million local school bond.

That boiler runs 24/7 from November to May, heating the school facilities, providing hot water, and creating less stress for maintenance staff. At the time of installation, the wood system cost half as much as diesel to operate.

Read more about that project here.

 

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The building that houses the wood chip boiler for Forks Middle School and Forks High School.

Did you know?

Today is National Bioenergy Day, and this week is National Forest Products Week. Across the country today, communities are highlighting the ecological, social, and economic benefits of a locally sourced renewable wood energy industry.