Rutland Plywood has taken its waste-fired steam production to the next level – by generating electricity and selling it to the local utility.
The Vermont-based manufacturer of hardwood laminates has for decades burned wood waste to generate process steam, and designed its manufacturing to work well with steam power, Sustainable Plant reports. Rutland harnesses high-pressure steam for kilns, veneer dryers, hot presses and autoclaves, and uses low-pressure steam to condition logs and heat its facilities.
More recently, the company invested over a million dollars to build a wood-fired cogeneration plant, which directs excess high-pressure steam to a 400 kW turbine and generator. Rutland feeds the electricity into the grid and gets paid monthly, under a 20-year contract, at a premium of about six cents over the market rate. It expects payback in under five years, with help from a US Treasury 1603 grant, which rebated 30 percent of project costs.
Of the steam Rutland generates, about half goes into its manufacturing and half to the cogeneration plant. The company does not itself use any of the generator’s electricity.
The wood and paper industries are highly energy-intensive, but are also among the most active sectors in waste-to-energy, since wood waste provides an obvious biomass fuel source. In 2011, Weyerhaeuser drew about 77 percent of its power from biomass fuels including bark and wood residuals, and that year the company also installed a waste-heat-to-energy plant to provide its Greenville, N.C. facility with about 4.5 million kWh a year. The plant should displace more than 9 million pounds of carbon dioxide equivalent each year, the company says.
Similarly, International Paper reported that in 2010, onsite generation accounted for 63 percent of the electricity consumed by its global pulp and paper manufacturing facilities, with the company meeting nearly 70 percent of its energy requirements with renewable biomass such as bark and wood residuals. Verso Paper Corp. uses waste wood to generate electricity, consumed on-site; and last year West Fraser Timber Company announced plans to generate 13 MW of power for its British Columbia plant and the province as a whole, using wood chips converted to biomass fuel.
According to the American Council on Renewable Energy, Vermont’s greatest renewable energy potential lies in its biomass sector – specifically, wood. Nearly 80 percent of Vermont is forested, which means the state offers a ready and sustainable resource for developing wood-based technologies, according to Foresight Science & Technology analyst Dick McCarrick.
