Manure Manager

Features Applications Beef
Natural Gas

April 28, 2008  by Paul MacDonald

Hilarides Dairy, a large
California operation, is finding there’s plenty of energy in the
natural gas released by manure, enough to put two generators in place
and supply almost all of the dairy’s power requirements.


Hilarides Dairy, a large California operation, is finding there’s plenty of energy in the natural gas released by manure, enough to put two generators in place and supply almost all of the dairy’s power requirements.

    The recent move to a large single central dairy facility on one site—from three separate, smaller dairies—offered California’s Hilarides Dairy the opportunity to achieve some much desired economies of scale, but it also presented the family-owned operation with the opportunity to set up its manure management operation from scratch.

    Dairy general manager Rob Hilarides was quick to seize the moment and has set up a modern manure management system that includes a bonus—a biogas system that now delivers half of the power required by the dairy operation. And with the expected addition of another generating unit, it will soon meet close to all of the energy needs of this 5,500-head dairy and heifer operation.


gas2The Hilarides dairy operation consists of open corrals and free stall barns, with milk cows kept mostly in the free stalls. All the alleys are flush system, with the flush water going through separation ponds.

    Rob Hilarides comes from a dairy background—his parents and grandparents had their own dairy operation in California. So it was little surprise that when Rob and wife Jeannie moved to the San Joaquin Valley, they started custom raising dairy heifers and eventually worked into milking cows. The Hilarides operated their dairies for years on three rented sites, two of them on land near where they are now in Lindsay, California. While they were able to achieve some efficiencies having three dairy operations, one of the sites was some 30 miles away. And with the three separate sites, there was no way to have a single manure management system.

    Several years ago, they decided to make a move to set up a single large dairy operation. Over a period of 25 years, they had purchased 2,400 acres, part of which, interestingly enough, used to be underwater. Local olive growers sent all their brine water to part of the site, to evaporate.

    But along the way to the new dairy, the Hilarides have had to go through a number of hoops and hurdles, including providing an extensive environmental impact report to Tulare County. This was the first time such a report had ever been required by the county. The report, by engineering firm Quad Knopf, cost the Hilarides $200,000, with the balance of the $800,000 cost paid for by the Dairy Industries Alliance, a group of dairy-related businesses. It took a total of three years to get a permit.

 Hilarides opts for
contract manure application

    In terms of the solids at the Hilarides Dairy, that material is taken out of the pit twice a year with excavators, and applied using the services of two local custom applicators, Brinkman Spreading and Hernandez Spreading.
    “Basically, the dry manure is applied to fields beyond the reach of our irrigation system, farther away from the heifer and dairy facility, places where it would be hard to get the liquid manure to,” says Rob Hilarides.

    The dry manure is applied to their acreage, and some is also sold to neighbors.

    The clear choice was to contract the dry manure application out, says Hilarides, rather than even consider doing it themselves. “When the contractors come, they have half-a-dozen spreaders, and can spread a big volume of manure over a large piece of acreage in a short period of time.  That’s generally how we like to do things—we want to get it done quick and get it done right, so we don’t lose any time getting our crops in the ground.”

    But 2005 finds the Hilarides set up with a modern facility with an 80-cow rotary parlor that milks 4,500 cows twice a day, and a secondary barn that handles the other 1,000 cows. Their herd is mostly Jerseys, but includes a fair number of crossbreeds. A small amount of milk is used for their own cheese making operation, but most of their production goes to the Hilmar Cheese Company in Hilmar, California.

    “Outside, we’ve got open corrals and free stall barns,” explains Hilarides. “Milk cows are kept mostly in the free stalls. All the alleys are flush system, and the flush water goes through separation ponds, 60 feet wide by 900 feet long. From there, it goes into our main lagoon, and we irrigate the farm out of that lagoon.” The six freestall barns are each 768 feet long, and have adjacent exercise pens.

    The systems at the dairy and the heifer ranch are entirely gravity flow, with the exception of when they move manure water from the main lagoon, where they have two US Farm Systems 40-horsepower flush pumps, and a 40-horsepower US Farm Systems unit that pumps the liquid out to the fields for irrigation.

    But in addition to using manure water for crop fertilizer, they are making use of another manure product: bio-gas. “It was part of the plan right from the start,” says Hilarides. “I started experimenting with this about four years ago, before we built the dairy.”

    Taking what he learned, he put a partial cover on one of the manure lagoons at the heifer ranch, about 250 feet by 150 feet, and pipes that bio-gas to a Caterpillar 125 Kw generator. It is now turning out enough energy to meet about half of the entire dairy/heifer operation’s requirements, and all of the modest energy requirements of the cheese making facility, Three Sisters Farmstead Cheese, which is run by Rob’s oldest daughter, Marisa.

    They are in the process of covering another larger lagoon at the heifer
operation, 220 feet by 1,100 feet, to capture enough gas for a second generator. A 60 ml HDPE cover supplied by Environmental Fabrics Inc is being used for the second lagoon.
    While the gas is collected at the heifer operation, it is piped to the dairy area, where the generator is located, and where they have the greatest power requirements.

    And at a time of rising energy and power prices, the more of their power requirements they can generate on the farm, the better, says Hilarides.

move to a large, single central dairy facility on one site—from three
separate, smaller dairies—offered Hilarides Dairy the opportunity to
set up a manure management
operation from scratch.

    “Another attraction of the system to me was in trying to collect a natural resource that has value to it,” says Hilarides. “After I saw how nicely it would burn from my experiments at the heifer operation, I could not see any reason why the gas could not be collected and burned, and power generated from it.”

    They have taken the approach that manure is not a waste product, but rather a resource with multiple possible uses. “We want to utilize that resource as much as possible, from the gases generated from it to the manure itself. It’s a beneficial commodity if you approach it that way. As long as you have enough farmland, there are some substantial savings in fertilizer costs.” And, he reasons, why should the gases from the manure just be released into the atmosphere, when they could be tapped and used to generate energy. “To me, manure is a valuable resource and I don’t want to see any of it go to waste.”

    Orchestrating the project on behalf of the Hilarides Dairy was Roy Sharp of Sharp Energy of Tulare, California, a firm that consults, designs and sets up waste management and energy production systems. The firm has completed a large number of similar projects, and Sharp himself has been successfully running his own manure to energy system on a large hog farm for 20 years.

    The details included some fairly complex electrical work to tie in with the system of their utility, Southern California Edison. “The requirements are really burdensome,” says Hilarides.

    They hired an electrical engineer, Gary Olsen out of nearby Fresno, to help them set up the system, and to shepherd them through the various hoops. “To interconnect with the system, you’ve got to meet all the requirements and have an interconnection agreement with the utility. That’s no small chore because their requirements are pretty substantial.”  To be fair, the requirements from the utility ensure that power flows smoothly in the system, and ensures that power is not flowing in the wrong direction, in—or eventually, out of—the dairy, when it is not supposed to. So there are safeguards for both the utility and the dairy.

    With the new centralized dairy facilities, they were able to bring all the power requirements into a single interconnection point. “Everything is wired to one meter, our flush pumps, domestic well, lights in the freestall and the milking equipment, so we can get maximum benefits from the generator. When the second generator comes on, we will be just about there in terms of meeting all of our energy requirements for the dairy.

    “Beyond that, we may consider putting in additional units at our own expense, if we have enough gas, and any additional power would be run through Southern Edison and its Net Energy Metering program.” This program allows power generating operations such as the Hilarides Dairy to send excess power into Edison’s grid, effectively offsetting their energy costs in other parts of the farm.

 Biogas concept simple,
but not inexpensive

    For any dairy operators thinking of setting up similar biogas systems to that in place at Hilarides Dairy, Rob Hilarides notes that it is expensive, and, as the saying goes, the devil can be in the details. “The concept itself is simple, it’s the details that can kill these projects,” he says.     
    “In our case, we were very fortunate in that we were able to participate in a grant program that ran for a while in California.”
    Under the program, the California Energy Commission, through Western United Resource Development and producer association Western United Dairymen, paid for 50 percent of the cost of the power generation system. “This was about a million-dollar project, so the program kicked in half of that, and that grant made it economically feasible to do it. We would not have gone ahead without that grant.”

    “We are an irrigated agricultural area here and don’t get a lot of rainfall, so we do a lot of pumping with electric wells, and they require a lot of power. So there could be a substantial cost benefit if we have enough gas and can participate in the program.” About half of their water comes through a canal system that originates in the mountains and runs through the San Joaquin Valley, but the remaining half has to be pumped from irrigation wells.

    The second power unit, as with the first, is a Caterpillar G342 generator, which was chosen for its simplicity, says Hilarides. “It’s a real straightforward design. It’s an older-style engine, non turbo-charged, non air-cooled, but it’s a real workhorse and it’s easy to work on. If there are any problems, they are easy to troubleshoot, and repair.” Both units were picked up used, and have been completely overhauled by a local company, Saltzman Auto Electric and Equipment of Tulare.

    The liquid manure that is providing all this biogas is mixed with ground and surface water and applied to crops using their irrigation system. The Hilarides double crop corn, wheat and also grow alfalfa.

    At this point in the process, having been in their new location for about 18 months, Hilarides has been able to put in place a number of efficiencies both on the manure management side, and in general, on the dairy and crop side.

    “It was hard to manage things the way things were before, with three operations spread out over 30 miles. It was difficult getting this new dairy through the permitting process, but it was worth the trouble. Now we have this single block of acreage that is contiguous and allows us to grow our own feed and apply the manure.

    “We don’t have to haul the feed any more than two miles and we don’t have to haul any of the dry manure more than two miles, and we can keep an eye on everything.”
    While the dairy operation is permitted for 9,000 cows—which would require additional freestall and carousel capacity—Hilarides says there is no timeline to ramp up to that level right now. For the time being, they are going to work on tweaking things with the existing operation, such as the installation of the additional generator, to get it operating as efficiently as possible.

gas4The Caterpillar G342 generator (left), the power unit for the biogas system, was chosen for its simplicity. “It’s a real workhorse and easy to work on,” says Rob Hilarides, dairy general manager.

    As for parting advice for others interesting in generating power from manure gas, Hilarides says they should do a thorough investigation before going down this path, but it can pay off. “I think it’s like anything else—you really have to do your homework and look into it.”

    He says having a good core team is important. “You need a project consultant, good electrical people, some good pipeline guys and someone who is familiar with running engines on natural gas or biogas. It’s a matter of pulling the right people together and then getting the job done.”


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