BY PETER BELAND
Nine electricity-producing methane digesters are under development throughout the state despite initial financing hurdles. Digesters, located on dairy farms, convert manure into electricity by capturing and burning methane produced by the anaerobic fermentation of the manure, gas that would otherwise go into the atmosphere.
Oregon is home to 140,000 cows on 150 farms that produce thousands of tons of manure annually, typically collected into large lagoons. According to Portland-based environmental nonprofit The Climate Trust, Oregon could go from producing 0.85 MW in dairy methane digester power to 45 MW if the sector was fully developed, enough to power 30,000 households for a year.
“These [methane digester] projects are about changing the way we manage waste streams,” says Energy Trust of Oregon biomass program manager Thad Roth of how the digesters can help turn the lagoons of excrement into energy and by-products such as fertilizers and animal bedding. “But the anchor tenant for all of this is still energy,” says Roth, stressing that most development is done by third-party engineering firms with a solid understanding of local and global energy markets.
Without involvement of such firms that understand how to capitalize on energy credit markets, dairy methane digesters would have a hard time to get off the ground. For instance, The Climate Trust can purchase so-called methane destruction credits to offset global warming and The Energy Trust can receive renewable energy credits in exchange for initial funding of a project credits that are transferred to Portland General Electric or Pacific Power.
Of the nine methane digester projects under development in Oregon, six are being developed by D.C-based energy firm Revolution Energy Solutions, the firm that built the $2.2 million digester at Lochmead Farms in Junction City that was operational late last year. The projects in Oregon could produce 7 MW in the next three years, many of which have backing in the form of BETC and other tax credits/ and over $20 million from private investors in New York City in a sector that most banks shy away from because of high overhead costs in an undeveloped market.
“Carbon credits are another revenue source these projects can taken advantage of,” says Climate Trust senior program manager Sheldon Zakreski. “But you have to be conservative in your timeline,” he says. “The big trick with methane digesters is that they have to get to that operational state.”
Zakreski remains optimistic about the future of digesters. “Ten years ago, wind was beyond business as usual,” he says. “Now there are times when wind is cheaper than gas. A great advantage of biogass for electric purposes is that it is a predictable source of energy.” According to Roth, 45 MW of methane digester power is the equivalent to 130 MW in wind power because wind power is only generated around 30% of the time in the Northwest due to inconstant winds.
Peter Beland is a contributor to Oregon Business.