|
|
|
Last Updated: Sep 26, 2008 - 12:55:16 PM |
FOR years, the cows at Green Mountain Dairy here produced only milk and
manure. But recently they have generated something else: electricity.
The farm is part of a growing alternative energy program that converts
the methane gas from cow manure into electricity that is sold to the
power utility’s grid.
Central Vermont Public Service, which supplies electricity to 158,000
customers around the state, was among the first utilities in the
country to draw electricity from cow manure on dairy farms. About 4,000
utility customers participate by agreeing to pay a premium for the
electricity.
“We realized we could help meet a customer demand for renewables, help
solve a manure management problem and make these farmers more
financially secure,” said Steve Costello, a spokesman for Central
Vermont Public Service.
Four Vermont dairy farms are producing electricity for the utility, and
two more are expected to be online by year’s end, Mr. Costello said.
The utility hopes to add six more farms by 2010.
Residents and businesses that get their electricity from the program
pay a premium of 4 cents a kilowatt hour above the typical rate of 12.5
cents. Most of that money goes to the farmers, who must purchase their
own equipment, which can run up to $2 million per farm. Most farmers
expect to make back their investment in 7 to 10 years.
The brothers who own Green Mountain Dairy, Bill and Brian Rowell, were
looking to squeeze more profit from their farm, where they have 1,050
cows and have begun acquiring 600 heifers. Milk prices had dipped and
they wanted another source of income.
They also thought that the huge amount of waste their cows produced
could be used for something other than fertilizer. So they decided to
give electricity a try, armed with about $750,000 in federal, state and
utility company grants.
“We saw this as an economic and environmental management tool,” Bill
Rowell said. “It’s helped to diversify our farm,” which was named the
2008 Vermont Dairy Farm of the Year.
The Rowells’ cows live in a barn where a mechanical scraper sweeps the
animals’ waste into a large drain. The waste is then pumped into a huge
sealed concrete tank known as a digester, which holds 21 days’ worth of
waste and is kept at a temperature of 101 degrees Fahrenheit. Anaerobic
bacteria break down the organic matter in the waste, producing a mix of
methane and other gases, known as bio-gas. The gas is burned in an
engine that runs an electrical generator.
The cow waste produces 250 to 300 kilowatts of electricity daily,
enough to power 300 to 350 homes, according to the utility.
“We’re making a resource out of a waste stream,” said Bill Rowell, who
is running for the State Senate.
In return, the Rowells receive a payment based on the wholesale cost of
power, which averages about 7 cents per kilowatt hour, plus the 4-cent
premium. Mr. Rowell said they earned about $200,000 from electricity
annually, and with the additional cows should receive $235,000 to
$240,000 in revenue from electricity.
The Rowells are also transforming commercial waste. The farm processes
about 500,000 gallons of waste and outdated ice cream from Ben &
Jerry’s each year and puts it in the digester. The free ice cream,
which the company drops off, helps the Rowells generate more
electricity and saves Ben & Jerry’s the cost of disposing of it.
“We’re improving our processes, and they’re improving theirs,” Mr.
Rowell said.
The digester produces more than electricity. After 21 days, the waste
is pumped through a separator, which siphons off the liquid into a silo
and drops the solids into a barn.
The liquid manure is used as fertilizer, while the solids are used for
cow bedding. The bedding saves the Rowells thousands of dollars a month
on sawdust, and they sell the excess to garden stores.
Other utilities across the country are purchasing power from farms as
part of their renewable energy portfolios. Some, like Central Vermont
Public Service, charge their customers a premium, while others do not.
Alliant Energy, which supplies electricity to rural customers in
Wisconsin, Iowa and Minnesota, draws power from four digesters and is
working to add more. About 20 independent farms in Wisconsin have
digesters and sell electricity to various utilities, said William A.
Johnson, manager of biofuels development at the utility.
“Our economy is agriculture, and people recognize that supporting the
industry is a positive,” Mr. Johnson said. The utility charges 2 cents
a kilowatt hour more for cow power.
“Rural customers, in particular, are very excited that something that
is considered by some to be a liability, manure, has become, in
essence, a resource,” Mr. Johnson said.
In Ohio, Buckeye Power went online with a digester at the end of August
and plans to turn waste from a chicken farm into electricity next year.
“We were interested in finding a type of green power that was, No. 1,
not intermittent, like wind or solar,” said Steve Oden, a spokesman for
Buckeye, which will not charge extra for the power.
Marie Audet’s family farm in Bridport, Vt., was the first in the
Central Vermont system and went online in 2005. The family invested
$1.3 million and expects to make that back in four years.
“We’re saving money by not using sawdust, reducing original waste by
recycling and generating revenue by selling electricity into the grid,”
Ms. Audet said.
And many customers here have chosen to pay more for power that is both
renewable and supports local farmers.
Maggie Hatch, who owns the Newbury Village Store in Newbury, Vt.,
operates half of the business with cow power. The renewable power adds
$200 to $400 a month to the store’s electric bill, but Ms. Hatch and
her husband, Gary, say it is worth it.
“It’s worth it to us to spend that money to help the producers and use
power that helps sustain the environment,” Ms. Hatch said. “When you
live in a place like we do, which is a beautiful part of the country,
you’re really aware of the environment and want to keep it that way.”
Source:Ocnus.net 2008
Top of Page
|
|
|
|