Wood to watts

Susan Moran, The Rocky Mountain News Reports:

Give him wood chips, coconut husks, corncobs, even chicken litter, and Robb Walt will turn it into electricity and heat.

"This stuff is so cool!," said the burly co-founder and chief executive of Community Power Corp., located just north of C-470 and just west of South Kipling Parkway in Jefferson County.

The company, founded in 1995, boasts it has developed the world's first non-polluting biomass-based power generator - a gasifier, in engineer-speak. A small team of engineers is designing the machines - each resembling an industrial-size copy machine or larger - for homes, small businesses and schools, particularly those situated way off the grid.

The terrorist attacks of Sept. 11, 2001, helped pique the public's appetite for domestic energy sources. And President Bush's push to thin out fire-prone national forests has spurred more federal financing for projects like Community Power's machine, which can turn wood and other forest residues into electricity.

"Today, there's a general acceptance that renewable energy is not just an experiment, it's an imperative; 9-11 has really changed the marketplace," Walt said. "Nowadays, it's much easier to justify investing in renewables."

Community Power is partly financed by the Department of Energy, through its National Renewable Energy Laboratory in Golden. "9-11 is somewhat changing the emphasis of our support to more heavily concentrate on trying to produce substitutes for imported oil, including gasification," said Richard Bain, group manager of NREL's biomass thermochemical conversion center. Gasification is a process in which solid fuel is vaporized to a gas.

Biomass, which includes plant matter, agricultural waste and landfill gas, already outpaces geothermal, wind and solar energy generation in the United States. In 2001 (the most recent figures available) it represented 75 percent, or 60 billion kilowatt-hours, of all non-hydro renewable energy generation in the nation, according to NREL.

Most of that generation comes from large-scale utility companies, including Burlington Electric in Vermont, that sell electricity to the grid.

Big thoughts

Walt is acting small while thinking big. His team, equipped with $5 million in financing, mostly from the Department of Energy, Shell Renewables, the U.S. Forest Service and the California Energy Commission, has been demonstrating Community Power's BioMax cookers in a handful of small towns in the United States. Additionally, a 15-kilowatt machine has been electrifying a remote village of 150 homes in the Philippines for three years using wasted coconut shells. Villagers turn the residual fiber into erosion-controlling mats and other products.

Walt aims to start making the machines for commercial use in the United States by late next year, at an estimated cost of $15,000 per unit. If the startup recruits corporate investors and manufacturing partners, Walt expects the price of each unit to drop considerably, making the technology more affordable to homeowners.

"We're writing a new chapter with small modular biopower," he said. "The broader part of our initiative is to offset our use of and dependence on fossil fuels and nuclear energy."

The BioMax system gasifies woody waste instead of incinerating it to make a renewable, gaseous fuel. In turn, this fuel-gas powers an engine or fuel cell to generate electricity and heat, making it an environmentally cleaner alternative to typical fossil fuel-based generators.

So how does Community Power's BioMax work In one end you pour a sack of wood chips, nut shells or pellets (considered the optimal fuel because they are small and dense) into an oxygen-starved tank- shaped gasifier, which heats the solid fuel until it forms a combustible gas (up to 800 degrees Celsius, or 1,472 degrees Fahrenheit). The so-called producer gas is a mixture of fuel gases such as hydrogen, carbon monoxide and methane.

Thermal energy producer

Residual tars and particulates are filtered out. The gasifier, along with the engine's coolant and exhaust, produces thermal energy, which can be used to heat water or dry grain. In future BioMax systems, CPC plans to incorporate an optional household cooling system that uses excess heat and a small amount of water and electricity.

According to Walt, roughly 60 pounds of wood chips morphs into 20 kilowatt-hours of energy - sufficient to run a typical three-bedroom home for a day.

The household machine's generator need not run more than five hours a day, thanks to a battery bank that stores the energy. Which is a good thing, given that the humming of two BioMax machines being demonstrated recently at CPC's office drowned out conversation within 10 feet of them. Walt suggests homeowners place the machines in a shed outside.

CPC hopes to resolve the noise problem by replacing the existing generator with hydrogen fuel cell technology, which is also more energy-efficient. "I predict that in five years, half of our systems will use fuel cells," Walt said. Fuel cell technology is advancing rapidly but is still very expensive.

So far, Community Power has designed 5-kilowatt (for homes) and 20-kilowatt Bio-Max machines, such as one powering a greenhouse at a Walden high school in northwest Colorado. Within two years, Walt expects to add 50- and 100-kilowatt systems (enough to power a school or business) to Community Power's product line. One cooker under development would convert poultry litter - a massive economic and environmental problem - into electricity and heat on-site at U.S. poultry farms.

The company also is working with Nike Corp. to develop biopower systems to apply in the shoe-manufacturing process, using factory waste as fuel for micro-factories in Thailand and elsewhere.

A huge market

"This could be a huge market for us," Walt said.

Skeptics of wood gasification argue that it devours too much of a not-so-easy-to-replenish natural resource. Walt acknowledges that his BioMax machines aren't for every home or town but that they make most economic and ecological sense in areas where there's plenty of wasted wood that would otherwise be left to rot or tossed - at a cost - in landfills (producing methane and other greenhouse gases).

Walt was hardly born a biomass evangelist. For years he installed solar power systems in Indonesian villages for Westinghouse. But he grew frustrated with the steep cost of delivering enough solar panels to satisfy villagers' insatiable thirst for TVs and other appliances. He left Westinghouse and formed a joint venture with a large Indonesian conglomerate hoping to electrify Sumatra's 44,000 villages. Then came the "Asian flu," which bankrupted Walt's corporate partner.

Walt returned to the United States, where he attended a renewable conference at NREL. A top scientist spoke of the promise of biomass. "Biomass - I couldn't even spell it," Walt recalled. "Gasifier sounded to me like a disease. I had no clue what it was."

With the help of Tom Reed, an inventor and engineer who Walt refers to as "the father of modern gasification," Walt began the quest to develop a small-scale, modular biomass gasifier. (Gasification dates back to the 1800s and took off during World War II. At that time more than a million gasifiers were used in Europe to power civilian cars when the military guzzled most of the precious gasoline supplies. But the systems were clunky and far from clean.)

"Gasifiers still aren't really there yet. It'll be awhile before you can go out and buy one and get a warranty on it," said Tim Maker, director of the Biomass Resource Center in Mont-pelier, Vt., a nonprofit dedicated to expediting the commercialization of biomass energy applications. "But CPC is definitely in a leadership position. They have something that's very close to commercialization." Maker has advised Community Power.

Walt and his team are test-running a 5-kilowatt BioMax machine that they plan to install in a Navajo hogan in Cameron, Ariz., next month. If that proves successful, Walt hopes to eventually install many more throughout the partly electrified region.

"This is bigger than just one hogan," he said. "Our approach is to go small and distribute lots of them. Never before has anyone had the opportunity to use wood to produce electricity, not just heat."

BioMax at the source

BioMax is the trade name used by Community Power Corp. for its trailer-mounted systems that convert woody biomass residues to electricity and thermal energy. Here are some other facts:

• Fuel sources: Wood chips from hard and soft wood, sawdust pellets, coconut shells, pecan shells and corncobs. Poultry litter is being tested.

• Electricity generation: The BioMax has a gasifier that converts wood chips, for example, to a mixture of fuel gases such as hydrogen, carbon monoxide and methane. This producer gas is combusted or mixed in an internal combustion engine, a stirling engine, a micro-turbine or fuel cell.

• Waste products: The BioMax uses a dry system to cool and clean the producer gas, eliminating the need to process large quantities of contaminated water, as found in wet scrubbers. Ash and char are stored and periodically combusted to ash that can be dispersed in the soil. Tars and soot are recycled through the gasifier.

Posted by glenn at August 19, 2003 02:40 PM | TrackBack