Colorado Springs Utilities plans to turn 60 tons of wood a day into energy.
The grounded wood chips will create about 4.5 megawatts of energy - about 2 percent of the total energy created daily by Drake Power Plant unit 5. But wood biofuel is considered by some experts to be carbon neutral and a more readily available source of energy than solar or wind, said George Luke, Utilities general manager, Energy Services Division.
"It's there when you need it," Luke said about the woody biomass. "With wind and solar you don't know when the fuel will be there."
Utilities will launch a one-year woody biomass pilot program Jan. 1 to determine whether burning wood should become part of the city-owned Utilities' renewable energy plan. The wood will be co-fired, or blended, with coal and even with its higher rate, it already has a buyer: Fort Carson.
Terry Meikle, Utilities energy supply manager, says the program has great promise.
He's been working on the concept of burning wood as fuel at Drake Power Plant since 2006. The issue he faced was the equipment it takes to smash the wood pieces into small enough bits before it goes into the burners - the same ones used for coal. Only Drake 5, built in 1962 with its older hammer pulverizers, had the capability.
It means the woody biomass pilot project will not require capital expense or additional personnel, Meikle said.
"We'll be using our existing blending machines - that's what is making this possible," he said. "There are a lot of environmentally awesome things going on here."
Some experts say woody biomass emits less sulfur and ash than coal. But it costs twice as much as coal to produce. Coal costs $1.92 per BTU (British thermal unit) while woody biomass costs $3.65 per BTU.
Part of the test program will be to measure costs and emissions, Luke said. And Utilities wants to determine whether local suppliers can provide 60 tons of wood a day.
Utilities will spend a little more than $1 million on a contract with Colorado Springs-based Rocky Top Resources for the wood supply and delivery. The company will deliver three semi-trailer loads of wood daily to the power plant, said Fred Martin, owner of Rocky Top Resources.
"It's a lot of wood," he said.
But Rocky Top will collect wood from a 50-mile radius, including from manufacturing companies, home builders, Fort Carson and tree trimmers, he said.
"We'll process it once through our grinding unit," Martin said. "We screen that material, run it through a second process to get it down to size - less than one inch diameter."
Fort Carson will buy 2.5 megawatts of the energy produced by the wood.
The post will pay a higher rate for the energy - 4.5 cents per kilowatt hour compared to 2.59 cents at the coal rate. It should cost the post about $490,000 a year. But the cost may be balanced by the environmental benefits, said Vince Guthrie, Fort Carson utility program manager.
"We need to diversify our energy portfolio," Guthrie said. "We are heavily weighted in fossil fuel now . . . we see there could be potential with woody biomass for long term. This is a good hedge."
Fort Carson is one of two posts in the country with "net zero" goals of energy, water and waste sustainability by 2020, Guthrie said. It means the post is trying to produce as much energy on site as it uses. But that plan also includes working with outside partners, like Colorado Springs Utilities, he said.
Fort Carson will provide about 10 to 15 percent of the daily wood requirement for the pilot program with wood mostly from crates and scrap. The post previously hired a contractor to haul the wood away and recycle it and now will save $96,000 a year on that contract to use toward buying the energy, Guthrie said.
"It's good for Fort Carson. It's good for the community. It's good for economic development," Guthrie said. "The wood is generated here, goes to Rocky Top and then is used for energy. Instead of importing coal from other places, it's a locally sourced resource."
The woody biofuel represents about 5 percent of Fort Carson's total energy use, Guthrie said.
"We want to prove the capability and see what the real economic potential is long term.," Guthrie said. "We are hoping those prices eventually come down."
Woody biomass was not among the 12 scenarios considered in a recent study on the possible decommissioning of Drake Power Plant. Among the scenarios studied, wind and solar energy were included in the mix on how to replace the coal-fired energy. The Colorado Springs Utilities Board will consider the 12 options in the coming months and expects to make a decision about Drake's fate by summer, officials have said.
Luke said there was not enough information on the real costs of burning wood for fuel at Drake's power plant to include in the Drake decommissioning study.
"The whole purpose in this pilot is to get enough information on the cost of biomass," Luke said. "Are there long-term positives and negatives to burn biomass day in and day out, 365 days a year?"