| RIVERDALE, California
RIVERDALE, California Imagine a vat of liquid
cow manure covering the area of five football fields and 33
feet deep. Meet California's most alternative new energy.
On a dairy farm in the Golden State's agricultural
heartland, utility PG&E Corp began on Tuesday producing natural
gas derived from manure, in what it hopes will be a new way to
power homes with renewable, if not entirely clean, energy.
The Vintage Dairy Biogas Project, the brainchild of life-
long dairyman David Albers, aims to provide the natural gas
needed to power 1,200 homes a day, Albers said at the
facility's inauguration ceremony.
"When most people see a pile of manure, they see a pile of
manure. We saw it as an opportunity for farmers, for utilities,
and for California," Albers said.
In addition to being a partner in the 5,000-head Vintage
Dairy, Albers is also president of BioEnergy Solutions, the
company that funded and built the facility which cost millions
of dollars. PG&E is simply a customer and the companies
declined to give details of project finances.
As cow manure decomposes, it produces methane, a greenhouse
gas more potent than carbon dioxide. Scientists say controlling
methane emissions from animals such as cows would be a major
step in addressing climate change.
Enter the Vintage Dairy project. As luck would have it,
methane can be captured and treated to produce renewable gas,
and California regulators have directed PG&E and other
utilities to make renewable energy at least 20 percent of their
electricity supplies by 2010.
PG&E expects to reach 14 percent this year, thanks in small
part at least to its partnership with BioEnergy Solutions.
To tap the renewable gas from cow manure, the Vintage Dairy
farm first flushes manure into a large, octagonal pit, where it
becomes about 99 percent water. It is then pumped into a
covered lagoon, first passing through a screen that filters out
large solids that eventually become the cows' bedding.
The covered lagoon, or "digester," is the size of nearly
five football fields and about 33 feet deep. It is lined with
plastic to protect the ground water and the cover, made of high
density polyethylene, is held down at the edges by concrete.
The digester's cover was sunken into the lagoon on Tuesday, but
officials said it would be taut and raised in a few days as the
gas collects underneath it.
Weights on top of the digester channel the gas to the small
facility where it is "scrubbed" of hydrogen sulfide and carbon
dioxide. The end product is "close to 99 percent pure methane"
according to BioEnergy Chief Operating Officer Thomas Hintz.
Once it is treated, the gas is injected into PG&E's
pipeline, where it will be shipped to a power plant in Northern
According to Albers, PG&E and California state officials,
biogas is a major opportunity for dairy farmers to make extra
revenue while helping the environment.
"There are a lot of lagoons like this in California that
don't have lining in them," said James Boyd, commissioner and
vice chair of the California Energy Commission. "There is a
business case to be made for this ... climate change has really
provided the incentive to do this."
Both BioEnergy Solutions and PG&E are actively courting
dairy farmers, whose cow manure is now simply being used as
fertilizer, allowing the methane to be released into the air as
a greenhouse gas.
"With nearly 2 million dairy cows in California, the
potential is great," said Roy Kuga, vice president of energy
supply for San Fransisco-based PG&E. The company has a
partnership with another company, Microgy, which is currently
setting up biogas projects at three California dairies.
In practice, however, not every dairy could participate in
such a project because some are not located close enough to the
necessary gas transmission lines, PG&E officials said.
Still, for now there are plenty of dairies to get on board.
A second dairy in Fresno county has already agreed to join the
Vintage Dairy project and Albers estimated gas from the two
dairies combined could power 2,500 homes a day. The Vintage
Dairy facility could accommodate gas from up to two or three
more dairies, depending on the size, officials said.
(Editing by Andre Grenon)