State regulators today resolved one of the more nettlesome conundrums of green energy: Do forests and tree farms count as a renewable energy resource?
The N.C. Utilities Commission said that they do, clearing the way for power companies to harvest entire trees for wood chips to be used as a fuel in power plants. Wood and other biomass are expected to supply much of the alternative fuel that in the coming decades will offset the state's heavy reliance on coal and nuclear power to generate electricity.
Duke Energy, the state's biggest power company, is already blending wood chips with coal to meet its green energy mandates under the state's 2007 energy law, which requires power companies to shift to alternative energy sources.
"This decision by the commission further reinforces that biomass, including woody biomass derived from whole trees, is a viable renewable resource for North Carolina," said Duke spokesman Jason Walls.
The state law includes biomass as an alternative fuel, but doesn't define whether wood waste is merely sawdust and other scraps, or whether forests and tree farms also qualify.
Environmental groups fought Duke's request, contending that counting whole trees as a renewable fuel would risk the state's forest to over-harvesting. The advocates found an ally in Utilities Commissioner William Culpepper, who disagreed with his colleagues' decision.
"I am unable to accept the idea of the state legislature enacting law that permits the clear cutting of old growth forest land for electricity generation purposes without providing concomitant requirements for best forestry practices and/or other sustainability measures," Culpepper wrote in his dissent.
Duke and other power providers argued the state lacks sufficient amounts of wood waste as a stead fuel source. The company currently uses whole trees harvested through sustainable forestry practices, Walls said.
Last year the company issued a request for information for biomass fuel supplies, and the predominant biomass fuel offered was derived from whole trees.
Duke has been testing various blends of coal and wood chips at two power plants: its Buck plant in Salisbury, and the Lee plant in Williamson, S.C. Wood typically accounts for less than 5 percent of the fuel used in the mix.
The company plans to continue using Lee and Buck for further evaluation of co-firing wood and coal. In addition to whole trees, Duke also plans to buy logging scraps, sawdust and pre-commercial thinnings.
"For energy crops to be a viable fuel source, potential developers first need operational facilities with a demonstrated and projectable appetite for such fuel," Duke wrote in a filing.