The combustion of biomass sparks savings in energy and reductions in greenhouse gas (GHG) emissions. Pioneered in Europe over 20 years ago, the technology has been implemented in industrial and educational applications since the early 2000s.
Engineers and experts think increased familiarity with biomass projects will lead to similar systems being adopted at other sites. Take advantage of alternative fuels to slash your energy budget.
How It Works
Biomass comes in many forms – wood chips, industrial byproducts, and dedicated energy crops.
Burning biomass does not result in new CO2 emissions because when plants grow, they absorb CO2 from the atmosphere and release oxygen by photosynthesis. But when fossil fuels are burned, resulting emissions add to the global inventory of CO2 because the carbon in the fuel came from underground rather than the atmosphere.
When both biomass and coal are burned, thermal energy is produced and used for electric power and heating, but biomass can displace coal at a fraction of the cost.
Oats Heat Up Campus
In 2003, the University of Iowa (UI) Power Plant partnered with Quaker Oats to utilize the firm’s leftover oat hulls, a byproduct of the cereal making process. Oat hulls are roughly half the cost of coal per BTU. Eight months of testing brought about modifications to the circulating fluidized bed boiler to allow the co-firing of coal and biomass.
“We spent about $1 million to figure out everything, and the plant is still running on the system we built for testing 10 years later,” says Ferman Milster, principal engineer of renewables for the UI. “It’s paying back pretty well.”
In its first year, the biomass project displaced 11,511 tons of coal and avoided $391,299 in fuel costs. Nine years later, it displaced 16,929 tons of coal and saved $950,880 in 2011 alone.
To date, the total tonnage of coal displaced is 168,915, with savings of $6,814,352, while 376,141 tons of CO2 emissions have been prevented.
“The UI adopted several sustainability targets in fall 2010, and this project is essential to our goal of achieving 40% renewable energy by 2020,” explains Elizabeth Christiansen, director of the UI’s Office of Sustainability.
To do this, the university must displace 60% of coal usage, explains Milster. Biomass currently accounts for an average of 12% of the UI’s energy consumption while costing only around 3% of the energy budget.
“We want to be able to blend biomass with coal in ever-increasing portions without major modifications,” says Milster, explaining that this requires a logistic supply chain.
The UI is considering various forms of timber and will plant 15 acres of the perennial grass miscanthus in spring 2013 and another 100 acres in 2014, with plans to add 1,000-2,000 acres each following year toward their ultimate goal of 10,000 acres.
Could It Work for You?
A major educational institution has the resources necessary for a biomass project, but can this be implemented elsewhere?
“There has been a lot done on a smaller scale abroad. It is not uncommon to find buildings that have their own biomass boiler,” Milster says, adding that these boilers are also available in the U.S. “The technology is there, but we don’t yet have a strong supply chain nor a general acceptance of the technology.”
A supply of dedicated fuel crops could provide a more stable source of revenue for farmers, since the cost won’t fluctuate like for agricultural crops. Therefore, biomass invokes what Milster calls an economic “win-win-win” – good for the organization, the state, and the local economy.
“There are no technical barriers. As bigger projects come online, you’ll see more acceptance,” he explains. “It really takes a long-term commitment.”
The UI is excited to pave the way for projects like this in the future.
“We’re trying to add to the body of knowledge, so if you want to go out and replicate this, we’re sort of writing the history,” Christiansen says. “We’re pulling in many different partners on the federal, state, local, and even private sector. We’re all learning together and helping contribute to change.”
Chris Curtland ([email protected]) is assistant editor of BUILDINGS.