December 14, 2011

SW Michigan dairy turns cow manure into energy


WMUK Local

By: Brian Peterson
Hamilton, MI
December 11, 2011
WMUK

 

Scenic View Dairy bio-digester

Scenic View Dairy electric generator
Ever wonder where the electricity that powers your lights, appliances, and electrical devices comes from? You might be surprised that some of it may come from a dairy farm, as WMUK’s Brian Petersen explains:

Power generation may not be the first thing you associate with dairy farms. But the cows at Scenic View Dairy near Fennville produce more than just milk.

[Andy Austin] “The Scenic View Dairy Fennville facility implemented the anaerobic digester system in the summer of 2006, began producing electricity in the fall of 2006. It is on a 1900 cow head milking dairy with three complete mix anaerobic digesters.”

That’s Andy Austin, Scenic View Dairy’s Digester Manager. Anaerobic digesters use microorganisms to break down cow manure. The 22-day process ultimately produces bio-gas. Burning that bio-gas to power a generator converts it into electricity. Scenic View Dairy sells the energy to Consumers Energy which distributes it throughout its system. The utility’s Principal Financial Analyst, Mark Devereaux, says energy from such non-traditional sources represents only a small proportion of the energy on the grid:

[Mark Devereaux] “Consumers Energy has been announcing to its customers and in its public announcements that about five percent of the energy that is purchased and generated by the utility comes from renewable energy sources.”

That includes wind and solar as well as these biomass facilities. Devereaux says state law requires Consumers Energy to produce and distribute electricity generated using renewable sources. But he says another factor also contributes to the company seeking new sources of renewable energy.

[Mark Devereaux] “There is always the incentive from customer demand because there is a sizeable portion of our customer base that wants renewable energy, they want to see it developed, they want to purchase the output in some way from it.”

For Scenic View Dairy, using anaerobic digesters serves several purposes. It eases manure management, produces electricity it can use on-site, and provides an important income stream. Part of that revenue comes from selling electricity to Consumers Energy. But Peter Freed, a director at TerraPass, a carbon offset and renewable energy company in San Francisco, says it works with Scenic View Dairy to capture other revenue.

[Peter Freed] “We work with a bunch of different dairy farms that have anaerobic digesters and also with landfill projects across the country that are capturing and destroying methane gas to help them create carbon offsets and then to bring some financial benefits to the projects for the environmental good that those projects do.”

What is a carbon offset? Freed explains it this way:

[Peter Freed] “What the carbon offset is, is we are looking at the destruction of methane gas that would otherwise have gone into the atmosphere and contributed to climate change, to global warming.”

Scenic View Dairy has meters in its digester facility that track how much methane has been converted into electricity. TerraPass buys those carbon credits from the dairy and sells them as offsets. Some go to companies but TerraPass also sells them to individuals who want to offset their own greenhouse gas emissions. For example, Freed says people can track emissions generated by their vehicles:

[Peter Freed] “So, on our website, we have calculators and you can enter in the make and the model of their car, how many miles you put on it per year, and then using standardized factors from the EPA we can figure out how many emissions your car would have put out in the course of a year and then you would buy an equivalent amount to mitigate the impact of those emissions.”

Freed says the smallest amount of carbon offsets you can buy is equivalent to a thousand pounds of carbon, which currently sells for $5.95. Increasing consumer demand for these offsets provides Scenic View Dairy another benefit from building the anaerobic digesters, which cost $3.2 million.

The digesters generate more than just electricity according to the dairy’s Andy Austin.

[Andy Austin] “The uniqueness of this facility was it was the first one in the country that could produce both the electricity and the gas operating system which produce the natural gas or bio-methane and sold them both back to their respective grids.”

The anaerobic bio-digester at Scenic View Diary does provide economic returns but Austin says that wasn’t the primary factor that persuaded the dairy’s owners to install it.

[Andy Austin] “The major reason was to be ahead of the curve, they want to be innovative.”

There are thousands of dairies around the country but very few have bio-digesters. Peter Freed at TerraPass suggests that another motivation persuades some owners to install them.

[Peter Freed] “There are only 150 digesters in the United States so what they are doing is really on the cutting edge of technology, it is on the cutting edge of environmental responsibility and its not like it’s a big profit center for them it was really a personal drive to do something good for the environment that caused them to put that in.”

Consumers Energy currently has four contracts with dairy digester facilities. But the renewable portfolio standard the state passed requires increased electricity production from renewable sources. Officials at Consumers Energy and the Michigan Public Service Commission say they expect more of these facilities to be built in the future, in part due to the new standard. That means it will become more likely that electricity in your home may have come from that most unlikely of places: a dairy farm.

 



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