Pioneer manure power producers
April 4, 2008 by Paul MacDonald
The Vander Haak dairy is a pioneer operation in its region, having worked with a strong set of suppliers to become the first dairy in the state of Washington to install a digester, a system that is now delivering manure-derived power to the grid.
The Vander Haak dairy is a pioneer
operation in its region, having worked with a strong set of suppliers
to become the first dairy in the state of Washington to install a
digester, a system that is now delivering manure-derived power to the
Washington dairyman Darryl Vander Haak is up to speed on all the technical and engineering details of the new manure methane digester on his farm.
When asked whether he had any suggestions for other dairy operations who are now considering digester equipment, he replied that they need to do their research and take a thorough look at what is out there. “But my overall theory is that if the digester doesn’t work like a cow’s stomach, it’s not going to work.”
A mixed plug flow digester designed and engineered by GHD Inc of Wisconsin is working like that cow’s stomach these days on the Vander Haak dairy in northwestern Washington. The accompanying generating system has started providing power to Puget Sound Energy, directly into the grid.
While other dairy producing states have their share of digesters, this is the first one in Washington State, and is bound to be watched carefully by other dairy operators in the region.
|Darryl Vander Haak at the generating system’s control panel. On an ongoing basis, the system provides enough power to generate electricity for 180 average homes.|
Vander Haak started the dairy farm with his brother more than 30 years ago, and these days his sons Steve and Tim are also involved. In addition to the 600 head of dairy cattle, they also have a small hog operation of about 100 head.
Vander Haak notes that the dairy is operating in a generally environmentally conscious state—Washington—with regulations that they need to keep on top of.
While Vander Haak had been considering going the digester route for a while, the fact that it was funded 25 percent by the USDA, 10 percent by the NRCS and 15 percent by the Washington State University/Paul G Allen Family Foundation’s Climate Friendly Farming Project made the decision easier to make. “Digesters have always kind of intrigued me, but the grants we received kind of put it over the top in terms of it being economically feasible,” he says. “It all seems to fit together.”
Construction started in June 2004 on the $1.2 million digester project and it was up and running in early November 2005. Construction had to be completed by November due to an eagle’s nest being nearby. This area of Washington is spotted owl country, and they take the environment seriously.
That said, government authorities—especially Whatcom County—were very forthcoming with the necessary approvals. They are as interested as Vander Haak in seeing this progressive manure management method move forward, since there are a number of large dairies in the county. “That’s in part why I think things went ahead as smoothly as they did. They were very much on side with what we wanted to do,” Vander Haak relates.
While it is still early in the start-up, the results so far have been very positive. “We really haven’t had any setbacks as we’ve gone along. We had some temperature problems at the beginning, and that’s probably the most crucial part of the digester, being able to control your temperatures.
“But it seems like you are able to control the temperatures better with the GHD system than with other systems. You want to get the right temperature, get bacteria growing, and generating the gas.”
|Taking the gas from the digester and generating the power is a Caterpillar G398 engine, from Martin Machinery. “Everything is computer controlled,” notes Darryl Vander Haak. “Martin Machinery can call the engine up every morning to see what it is producing.”|
Taking that gas from the digester and generating the power is a Caterpillar G398 engine, supplied by Martin Machinery of Latham, Missouri. The company gets high marks for their service from Vander Haak. “They are good people to deal with. I’m very pleased with their service.” Vander Haak notes that the G398 engine they supplied features the latest technology. “Everything is computer operated. Martin Machinery can call the engine up and see if anything is wrong over the phone. They can check every morning to see what it is producing.”
Vander Haak does the same; some days, he says, he checks the kilowatts being put out by the engine before he checks the milk tanks. On a recent day, it was doing just fine, generating a steady 275 kilowatts an hour. On an ongoing basis, the system provides enough power to generate electricity for 180 average homes. “Probably the most impressive thing about the whole system is how much gas comes out and the power it can generate,” he says.
Since the digester venture, and the infrastructure that goes with it, is brand new to the Vander Haak dairy, there is a need to be comfortable with all of their suppliers and the after-service. The suppliers have understood this, often going the extra mile in terms of service.
Partnering works for Vander Haak
An important part of the approach to installing a digester at the
Vander Haak dairy involved partnering up with a local firm, Andgar
Andgar represents GHD Inc on an exclusive basis
Andgar manages the system on the Vander Haak farm. It also handled the negotiations and the
resulting agreement with Puget Sound Energy, and plugging the power
from the Vander Haak digester and generation system into the grid.
Andgar offers complete turnkey project design, fabrication,
construction and project management. The company also offers digester
maintenance services for ongoing operations.
“It’s worked out quite well,” says Darryl Vander Haak. “It was easy
from our perspective. The Andgar people were on site quite a bit during construction.” They were also available
following installation, to do the inevitable tweaking of equipment.
Vander Haak notes the farm did its own homework before opting for
Andgar and the GHD system, touring a number of dairy operations in the
US Midwest with digesters. “We felt the GHD system was efficient. It was probably a little more costly
than some of the other systems, but it works the way it is supposed to.”
Other companies involved with the project included Bauer, which supplied the separation system. In addition to the Bauer separator, the operation also has a high pressure Bauer pump which in turn is fed by a Houle manure pit pump.
This all forms part of the manure transportation system for one of Vander Haak’s two barns. The digester sits near one of the barns and manure from a second barn is pumped to the farm’s one million-gallon manure storage pit via a 1.2-mile pipeline, hence the pump infrastructure. “We had some people doubting whether we could pump the manure, but it has worked out so far,” says Vander Haak.
In addition, the digester is also handling manure trucked in from two nearby dairies, with a combined cow count of 600. Manure from these two dairies, along with manure from the Vander Haak dairy, is pumped into the manure collection pit. Longer term, a pipeline will likely be built to link up these off-site dairies. The digester also processes some food waste, mostly from local fish processing plants.
The system is designed to handle up to 45,000 gallons of manure daily, though it is currently handling about 35,000 gallons a day, all of that creating methane, liquids and solids. The liquid material is applied to the Vander Haak’s 400 acres of farmland.
While some dairies install digesters as part of an expansion, Vander Haak says they will likely stay around their current herd size. They are limited in terms of land, in that their operation is right up against the Canadian border.
With the digester humming along nicely, the Vander Haak family is now focusing on ramping up the dry materials operation. In addition to being used for bedding, it is currently sold to a small number of nurseries and raspberry operations in the region, but they need more customers. Vander Haak says this has been one of the biggest challenges of the whole project.
“It’s an area in which we have not yet met our expectations, but we’re new to it and have not had a lot of time to be out there selling the product. But word is starting to get out there. I was at a nursery conference recently and the nursery people were excited about it.” With the cost of peat moss rising, separated material looks better and better for nurseries. Hitting fiber sales targets is a part of achieving a payback period of seven to 10 years for the project. “I think we will meet those expectations, especially if fiber sales start happening. All of the rest of our projections with the project have been achieved, above and beyond, and we’ll just have to work on the solids side.”
On the materials side, the Vander Haaks expect to be among the beneficiaries of a research program now underway at Washington State University.
Researchers at the university have received a Conservation Innovation Grant to “beef-up” digester co-products. The $283,000 grant was made possible through USDA’s Natural Resources Conservation Service Conservation Innovation Grant program.
A team of researchers at WSU’s College of Agriculture, Human and Natural Resource Sciences is using the grant to produce high quality fiber and fertilizer as co-products from anaerobic digestion. Essentially, the team is exploring methods to extract from liquid manure two high-value products: a high quality fiber that can substitute for peat moss as a type of “super soil conditioner” and a slow-release fertilizer.
The fibrous, organic material is said to be a perfect soil conditioner for nursery plantings and home gardening, and the slow-release, crystallized solid called struvite is rich in nutrients, including nitrogen and phosphorus. The key for researchers is to find ways to optimize the production of the nutrient-rich struvite and the fibrous, organic material and to perhaps effectively combine the two for effective commercial sale.
“If we can find a commercially viable way of doing this,” says Shulin Chen one of the researchers, “agricultural producers could have an additional stream of revenue, and that would encourage the use of anaerobic digesters and improve the economic viability of agricultural operations.”
|The Bauer separator on the Vander Haak farm receives a bit of tweaking. With the digester and energy system humming along nicely, the farm is now focusing on the dry materials operation and finding new markets and customers.|
According to Chen, in the Pacific Northwest—with its relatively inexpensive electricity—the revenue from digester power generation is not sufficient by itself to offset the cost of the installation, maintenance and operation of small to mid-size digesters. So the fiber needs to be acceptable in higher value markets, such as a replacement for peat moss in the ornamental industry, in order for the digesters to be economically viable, adds Craig MacConnell, another of the researchers.
“We see this potential market niche as an opportunity for agricultural producers throughout the country,” MacConnell says. “Our challenge is to find a practical way to improve the quality of the fibrous product and to extract and utilize the nutrients in an economical and environmentally sustainable way.”
The NRCS Conservation Innovation Grant complements the current digester and byproduct work that are a part of the larger Climate Friendly Farming (CFF) initiative led by the university’s Center for Sustaining Agriculture and Natural Resources. The CFF initiative is working to move agriculture from a source of greenhouse gas emissions to a sink, while maintaining profitability and other environmental gains. Major funding is provided by the Paul G Allen Charitable Foundation. Allan is a co-founder of Microsoft.
In terms of the power side, Puget Sound Energy is clearly interested in the Vander Haak dairy digester project, and perhaps further manure digester projects, as part of an initiative to produce “green power.” The company says its Green Power Program is one of the top 10 Green Power Programs in the country.
The initiative seems to have struck a chord with Puget Sound Energy customers. According to the utility, businesses like CH2M Hill, FedEx Kinko’s and IKEA have made the decision to buy renewable “green power” to cover a portion of their electric consumption.
While the arrangement with Puget Power is working out fine, with power flowing into the grid and the dairy farm receiving payments, Vander Haak says there may be other, better financial returns for the gases generated by the digester. Revenues might be greater if it was transferred to a greenhouse operation and used to generate heat. There are extensive greenhouse operations just across the border in Canada—producing vegetables year round—and they have seen the price of natural gas rise significantly in the last several years. Using gas powered from manure could be very attractive to these operations.
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