By year's end, Portland General Electric will fire up its 550-megawatt power plant in Boardman for a daylong test burn, feeding 8,000 tons of pulverized, roasted wood into its boilers instead of the usual diet of coal.

The exercise is meant to gauge whether the aging fossil fuel plant could reliably generate electricity using renewable feedstock such as "torrefied" wood after its scheduled closure in 2020. If it works -- technically, economically and environmentally -- Oregon's only coal-fired power plant could one day become the country's largest biomass power plant.

It's an uncertain, embryonic effort, but some believe the payoff could be substantial. The conversion of Boardman and other coal plants could extend the life of existing equipment, benefiting ratepayers, while helping utilities comply with state renewable power mandates. It could cut pollution from power plants and logging operations. And it could boost forest restoration efforts, particularly in overstocked national forests east of the Cascades, by creating a viable market for the small trees, tree tops and limbs left over from thinning and logging projects.

"There are job creation opportunities. We can take more material out of the woods. It's a big winner -- if it works," said Bruce Daucsavage, president of Prineville-based Ochoco Lumber Co., which operates the only remaining sawmill in Grant County.

Yet many conservation and climate advocacy groups are hoping it won't work. Biomass may be a renewable resource, they say, but it is not clean, particularly when it comes to emissions of greenhouse gases. Replacing coal with another carbon-emitting resource is a step in the wrong direction, they maintain, and would only pillage forests that sequester carbon and help combat climate change today.

It's a hot debate. But biomass energy projects are inching forward in Oregon.

Ochoco Lumber has partnered with the Bonneville Environmental Foundation and the U.S. Endowment for Forestry and Communities to set up two pilot torrefaction lines at the Port of Morrow for the PGE test burn. The venture, called Oregon Torrefaction, is currently roasting wood chips at an idled tire recycling plant and a mobile unit trucked in from Idaho.

Meanwhile, a Japanese company announced its intention last week to build the first commercial scale torrefaction plant in Oregon by 2018. It plans to use technology developed by a Troutdale-based startup, HM3 Energy, with financial and technical support from the state clean tech incubator, Oregon BEST.

The plant would transform wood waste into biomass briquettes that can replace coal in existing plants. The company is hoping to tap markets in Japan, where the government is looking to reduce reliance on nuclear power and is subsidizing utilities to use biomass in existing power plants.

"We in Oregon have an opportunity to show the country and even the world how to do biomass right," Sen. Ron Wyden said last week after touring HM3's pilot plant. "That means doing things in a way that makes economic sense, while also having long-term environmental benefits, and keeping in step with the best science."

Without saying it directly, Wyden was acknowledging the carbon controversy. Earlier this month, more than 20 forest conservation and climate advocacy groups in the state called on him and fellow Sen. Jeff Merkley to block provisions of the energy bill making its way through Congress that would classify biomass energy as "carbon neutral."

The groups say the designation is scientifically inaccurate. They also believe it would spur the expansion of large-scale biomass plants that spew greenhouse gases and other pollutants by protecting them from future carbon regulation.

"This could fundamentally change the industry, and we could see our forest management practices altered on the need to feed these plants," said Alexander Harris, a conservation organizer with the Sierra Club.

Concern over carbon

Carbon accounting is a complicated, controversial business in its own right. But proponents of biomass energy offer a fairly simple rationale for the carbon neutral designation: The carbon dioxide released when wood is harvested and burned ends up being sucked up and re-sequestered as new trees grow back.

From the environmentalists' standpoint, that's misleading at best, as a forest's natural cycle of decomposition and regrowth takes many decades, while biomass plants release the carbon instantaneously.

"It's not carbon neutral, and we should be having an honest debate about whether we want to be treating our forests as feedstock," said Dominick DellaSala, chief scientist at the Geos Institute in Ashland. "These are natural systems, not feedstock."

This file photo shows PGE's coal plant in Boardman, which is slated to shut in 2020. In the next few months, the utility plans to conduct a daylong test burn, using torrefied wood instead of coal to fuel the plant.

Linc Cannon, director of forest resources and taxation at the Oregon Forest & Industries Council, says the notion that mature trees would be harvested for energy production is misguided -- in the Northwest at least -- because biomass is such a low-value use of the wood.

When it comes to slash from harvests and thinning, he says, the environmental community needs to consider its alternative fate. Most of that material is burned in woods today or left to rot on the forest floor, where it can help fuel forest fires.

"Existing forest restoration contracts are going to be generating a whole bunch of biomass," Cannon said. "You either stack it and burn it, or you take it somewhere and you use it."

DellaSala says most of those projects don't make sense in the first place. He's skeptical they're doing much to control fires. To accomplish that, the scale of the thinning would have to be so massive that the associated carbon emissions would be extreme.

"We should be solving climate change by having reliable clean energy, and woody biomass is not the path we should be on," he said. "It doesn't work on a big industrial scale. You're just kicking the can down the road."

State's stance on biomass

The energy bill, including the biomass provisions, could move in the coming lame duck session. Wyden, a member of the Senate Energy and Natural Resources Committee, said he'd been talking with stakeholders on all sides.

"I am working hard with my colleagues on the energy bill conference committee to develop a solution that ensures any biomass policy is rooted in the science, is bipartisan, and moves Oregon and the entire country to a smarter carbon policy."

Oregon already classifies biomass energy as a renewable resource and allows utilities to count it toward the state's renewable energy standard. That mandate requires them to meet half of their customers' demand with renewable power by 2040.

The state also offers tax credits for the production, collection and transportation of biomass. And the Department of Environmental Quality doesn't regulate the carbon output at the handful of sawmills that burn biomass today to co-generate electricity and heat.

Oregon's Global Warming Commission is in the process of developing a carbon inventory for all state forests. That data could be used to analyze the effect of forest stewardship work in eastern Oregon, as well as the use of the biomass those projects produce for energy production.

Angus Duncan, chair of the commission, says that even if the fuel supply for biomass energy is limited to thinning projects intended to improve forest health, or clear invasive juniper trees, "We still need to be doing the carbon accounting."

"If we can come up with a forest biomass strategy that's compatible with a low carbon future, that will benefit those forest communities," he said. "You don't do that by passing a law that is contrary to what the science tells you."

Experimental industry

For now, in Oregon, the entire industry is still an experiment. A technical experiment. An environmental experiment. And maybe most of all, an economic experiment.

Matt Krumenauer, chief executive of Oregon Torrefaction, said no one is sure which torrefaction technology works best, how much it costs at a commercial scale, what species of wood makes the ideal fuel, or whether there's an adequate, sustainable supply of it.

He says the environmental question is crucial, but believes it is possible to use biomass in an appropriate way. As it stands, he said, the "biggest barrier to this technology is the market."

Utilities and other companies that could use the fuel don't want to make a long-term commitment to buy because they still don't have enough information about its viability or costs. But building a commercial-scale torrefier is expensive and not practical without a long-term buyer in place.

It's unclear whether the biomass provisions in the energy bill would affect the outcome of PGE's deliberations on Boardman. The company wouldn't be running a biomass plant full blast for much of the year, as it does the coal plant. Instead, it's likely to use the plant during periods of high demand, when other renewable resources like wind and solar may not be available.

"We've got a lot of hills to climb," Krumenauer said, and the first step is getting through PGE's test burn. "Enough standing around looking at each other. Let's actually do it and see if we can answer these questions."

tsickinger@oregonian.com

503-221-8505; @tedsickinger