PENDLETON — Portland General Electric is in its second year of testing the giant cane known as Arundo donax as a potential replacement for coal at the Boardman Power Plant.
But the utility is also looking at other biomass sources that may help fuel the power plant.
Wayne Lei, a research and development director for the utility, said 18 different products have been charred and tested at Washington State University in a scaled-down apparatus. Six of the substances have warranted a longer look, including corn stover, wheat straw, poplar chips, special biomass sorghum and a methane digester fiber — made from cow manure left over from the digesting process.
Researchers are testing whether the biomass has to be chipped, the percentage of liquid, solid and gas produced from the process as well as how much time is required and how much material can be charred at one time.
“We have not explored prices yet," Lei said. “Right now we’re looking at that it physically works."
Lei said giant cane is set to be the “anchor crop" for the power plant, but if other biomass proves usable they could reduce the acreage needed. According to PGE, the plant would need about 8,000 tons of biomass per day when the generator is operating.
Steve Corson, utility spokesman, said once the switch is made the plant will likely only run during the peak use seasons of summer and winter.
The utility has said it would need 60,000-80,000 acres of irrigated land if only giant cane were used as fuel for the plant. One reason biomass is so appealing to PGE is its use as a baseload power, compared with variable energy sources like wind and solar.
“To have a baseload renewable resource to turn on and off when the customer needs power is very appealing," Corson said. “It would also help us meet the requirement for the Renewable Portfolio Standard." The standard requires PGE to produce 25 percent of retail electric sales from renewable resources by the year 2025.
Corson said there are still a number of questions. One concern is the potential for the fast-growing perennial plant to become an invasive weed.