Small gasifier promises clean energy from wood waste
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As a demonstration, SBS Wood Shavings of Ruidoso, N.M., installed the first BioMax 15/35 gasifier. The unit converts the factory's wood waste into a peak generation of 15 kW. (Photo courtesy of Community Power Corp.)
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Mankind's oldest fuel source, wood, may become the latest trend in small renewable energy generators if Community Power Corp. succeeds in commercializing its line of biomass-fed gasifiers designed for homes, schools and small businesses, especially those in off-grid locations.
Not that biomass is an under-used renewable resource, according to the National Renewable Energy Laboratory. Biomass generation accounts for 75 percent of all non-hydro renewable energy generation in the nation. Most of that, however, comes from utility-scale operations that sell electricity to the grid. NREL, the U.S. Forest Service and the Littleton, Colo.-based company hope to change that in the near future, or as CPC cofounder and Chief Executive Robb Walt put it, "We're writing a new chapter with small modular biopower."
Biomass generator brings power, economic development to isolated regions
The collaboration is part of NREL's Small Modular Biopower Initiative to develop clean, efficient biomass generators of less than 5 megawatts for rural electrification and thermal applications. A 1997 grant from NREL enabled CPC to design and field test the prototype for the BioMax gasifier that converts woody residues into environmentally friendly energy.
Models range in size from 5-kW units for home use to 15-kW machines, enough to power a small business. The company is currently demonstrating six gasifiers in off-grid field applications. Those include one 15-kW unit using forest residue to power a greenhouse at North Park High School in Walden, Colo., and a 15-kW gasifier converting a Ruidoso, N.M., wood shaving factory's waste to energy. "The system is perfect for entrepreneurs whose businesses produce biomass residues," said NREL Senior Engineer John Scahill. "They can make the waste pile disappear while offsetting power and heating costs."
Originally, the initiative identified developing countries as the target market for small gasifier technology, "especially countries near the Equator," explained Scahill. "Those regions have a lot of biomass residues but no power. Once they get power, economic development opportunities open up."
CPC's exclusive focus on developing renewable energy-based products for unelectrified areas won the company funding to build a biomass gasifier for a rural village in the Philippines. The 15-kW unit gasifies coconut shells to make a gas for combustion in a spark-ignited engine. The engine drives a generator that powers a coconut-based enterprise. "They make biodegradable erosion control mats from the coconut fiber and sell the dust to process into a planting medium for orchids," said Walt. "It's a 100-percent sustainable and environmentally friendly business."
Forest Service sees fire prevention assistance in gasifier technology
Having successfully demonstrated the small-scale gasifier's commercial performance, CPC was ready to build and test more BioMax units. Unfortunately, that phase of development required more funding than was available through the SMB Initiative.
Another Federal initiative came to the rescue. The Bush Administration's 2002 Healthy Forest Initiative called for thinning the underbrush from thousands of acres of forest and rangeland to reduce fire danger. The biomass gasifier offered a means of using some of the tons residue resulting from the clearing. "The volume of material on the forest floor is enormous," said Scahill. "Turning it into an energy product might help to offset the $1,000-per-acre cost of the project."
The Forest Service contributed $1 million over two years to speed development of the gasifier project, which DOE matched. Shell Renewables and the California Energy Commission also funded a total of $5 million to build and deploy BioMax validation systems.
CPC placed gasifiers at four sites, selected from a nationwide Forest Service survey. The test sites record the machines' performance, helping the company refine the design. "Basically, we are asking them to run the machines into the ground," said Walt. "That information will help us to find and correct any flaws before BioMax goes into large-scale commercial production."
Commercial production is the key to making the technology affordable. Making the system modular and standardized so that it can be easily installed in the field will drive the cost per unit down. Walt aims to start making the machines for commercial use in the United States by mid-2005, at an estimated cost of $50,000 for a 20kW unit. If CPC recruits corporate investors and manufacturing partners, the price of each unit is likely to drop more.
Small modular biopower systems are most economical on a straight cost-per-kilowatt basis where there's on-site wood waste and a need for the available thermal energy, Walt acknowledged. If there are enough of those kind of sites in the U.S. and worldwide – and Walt believes there is—small biomass gasifiers could turn wood waste into the "hot" new alternative fuel source.
