Engineer seeks national digester push
Updated: Thursday, February 21, 2013 10:50 AM
Standardized designs would help dairies build digesters, Holden says
By DAN WHEAT
OLYMPIA -- Federal standardization of designs and construction loans could increase the number of anaerobic digesters at dairy farms, creating jobs and energy and helping the environment, a retired industrial engineer says.
The effort could be similar to the Rural Electrification Administration of the New Deal that shifted lagging rural electrification efforts in the West into high gear through standardized designs and loans, said Parker Holden, of Olympia.
He worked in industrial, marine and utility installation and servicing for Westinghouse for 15 years before spending 30 years as a pulp and paper industry electrical instrument and maintenance superintendent and plant engineer.
Digester technology -- turning cow manure into electricity or natural gas -- has been around for years but hasn't been used to its full potential, said Holden, 73.
Dairies haven't rushed to build anaerobic digesters because it's difficult to establish positive cash flow, electrical utilities can be uncooperative and Environmental Protection Agency approval can be difficult to obtain, he said.
The national electrical code is extremely weak in connection of independent power generation to electrical grids, he said.
"Some utilities give (digesters) lip service but put plenty of roadblocks in the way because nongenerating utilities often are uncomfortable with costs," he said.
Digesters and wastewater treatment systems also are usually not within dairy owners' areas of expertise, he said.
All of that could be rectified with standardized designs for electrical and natural gas production options for digesters so that dairies or groups of dairies could identify which options meet their needs rather than reinvent the wheel, Holden said.
Standardized options should be approved by the EPA and environmental groups so dairies or energy companies don't face those hurdles at each site, he said.
Recent advances in nutrient recovery technology make it commercially viable to extract marketable fertilizers from digesters, reducing the amount of nitrogen and phosphorous, sources of suspected groundwater contamination, by 60 to 70 percent, Dan Evans, president of Promus Energy, Seattle, has said.
A higher fiber solid that is left can be turned into a peat moss substitute of higher value than conventional composting from dairies, Evans said.
Such a multiplicity of benefits is the real selling point that dairy organizations, Washington State University or other land-grant agriculture universities should champion, Holden said.
Evans said he's leery of the government picking winners and losers and prefers innovators and the marketplace figuring out best designs. He said he favors government startup loans for viable projects. That's the "single most powerful thing" that could ramp up adoption of digesters, he said. It's hard to get projects financed, he said.
Promus Energy is in the design phase of a $13.5 million, biogas-to-renewable natural gas digester for two dairies near Sunnyside. Financing will be sought in another month or two and investors are interested, Evans said.