North Carolina power company Duke Energy has won approval to count five biomass co-generation units toward renewable energy standards.

Regulators rejected an attempt by opponents to intervene in the company's application to register two units at its Buck Steam Station plant and three units at its Lee Steam Station as producing renewable energy.

The 370MW Lee power plant in Williamson, South Carolina, started a biomass co-firing trial in July 2009 through the end of the year, generating 1,303 megawatt-hours of biomass power from coal blended with woodchips.

The 369MW Buck power plant in Salisbury, North Carolina, conducted a test in August and September last year generating 2,254MWh of power from coal blended with sawdust and woodchips.

Charlotte-based Duke Energy now plans to continue evaluating co-firing operations at the power plants, using material including wood waste, logging residues, forestry thinnings and woodchips from whole trees.

Opposition
Duke Energy is to use some wood chips from trees cleared from a site to be used as an ash pit, and because the trees are not to be replanted, opponents claimed the material could not count as "renewable" under North Carolina's renewable energy laws.

Opponents included lobby groups Environmental Defense Fund and Southern Environmental Law Center, along with farm and paper industry groups as well as rival power companies in the state.

However, the Utilities Commission ruled that the list of biomass materials in the state laws was "not an exhaustive or exclusive list" of materials that could count as renewable biomass, and that it had the power to consent materials on a case by case basis.

Commissioner William T Culpepper III ruled that Duke Energy could count wood fuel from whole trees as a "biomass resource" and a "renewable energy resource" under state laws, and may therefore earn renewable energy credits from the power produced.

Paper manufacturers Temple-Inland, Inc., and building products firm Georgia-Pacific attempted to block the Duke Energy biomass power project, concerned at the impact on wood feedstock prices.

The objections were filed 90 days late, with the companies stating that they had not understood the full implications of the biomass project in time.

Duke Energy argued that the objections were "grossly out of time" and merely repeated objections already taken by packaging company MeadWestvaco in the original hearings.

The Commission said there was "good cause" to deny the objections.