Power and Profit

January 3, 2011 09:33 AM
Power and Profit

Innovation runs deep at Brubaker Farms, located in Mount Joy in south central Pennsylvania.
Across the two-lane blacktop from the 900-cow dairy, a three-story, square-cut stone and brick house sits atop a well that has been spewing clear, cool springwater since at least 1729. Today, two modern pumps tap into this seemingly inexhaustible source of water to partially meet the needs of the dairy, a 500-head heifer barn and two poultry barns that house 26,000 broilers each.
The springhouse, as Luke Brubaker tells it, was built by Joseph Work, who fought for the patriot cause at the Battle of Brandywine during the Revolutionary War.

Bonus Content

Innovative Dairy Farmer of the Year Award

Brubaker Farm Video

Nutrient Trading

Nitrogen Calculation worksheet


A 150-kw solar system using 10,000 sq. ft. of solar panels was recently installed on the Brubakers’ 500-head heifer barn.


Brubaker Farms’ collage of farm recognition and distinction awards.


Using an innovative piping system, it supplied water not only for Work’s household and livestock but two neighboring farms as well.

This nearly three-century legacy of innovation lives on at Brubaker Farms, anchored by Luke while his sons Mike and Tony assume management and fiduciary roles.

 Some of the 21st-century innovations include a high-efficiency methane digester that uses college cafeteria food waste to increase gas production and more than 10,000 sq. ft. of solar panels fixed atop a barn roof.

These and a host of other innovative applications have led the Brubakers to be named the 2011 Innovative Dairy Farmers of the Year. The award is sponsored jointly by the International Dairy Foods Association and Dairy Today magazine.

The Brubakers’ methane digester generates serious revenue for the farm, a feat that is perhaps unparalleled by other dairy digesters across the country.

How do they do it? First and foremost, the Brubakers have been able to negotiate favorable electrical rates with their local utility, PPL Corporation. Those rates, which range from 10¢ per kw to 14¢ per kw in annual contracts, yield both a considerable and consistent income stream.

“We made more money on the electricity we sold last year than we did from the cows themselves,” Luke says. “If it wasn’t for the digester, our bottom line in 2009 would not have been good.”

“The digester gives us another profit center without adding extra cows,” Mike adds.

Pennsylvania laws also help. Net metering provisions allow on-farm electrical generators to connect to the power grid, letting meters run forward or backward depending on whether they are providing power to the grid or drawing power from it.

In addition, Pennsylvania utilities must purchase at least 8% of their power from alternative sources. That number will climb to 18% by the end of the decade, says Michael Wood, senior manager of corporate communications for PPL. 

The key to digester profitability, of course, is to keep the digester bugs fat and happy. The Brubaker digester is fed from the farm’s freestall barns that house the milking herd and a 500-head heifer barn.

Automatic scrapers move the manure from the pen alleys to flumes, where it flows to the influent holding tank of the digester. (Manure from the heifer barn is pushed 580' via a piston manure pump through a 12" pipe to the digester.)

Then, four times a day, the manure is fed into the complete mix digester, where it is digested by methane-producing microbes for 26 to 28 days.

The resulting methane powers a six-cylinder Guascor genset and keeps it humming 24/7 at 200 kw. At that rate, the generator puts out 4.8 megawatts of electricity each day, enough to power 150 to 200 homes.

Since September 2009, the Brubakers have also taken in 2,000 gal. to 3,000 gal. of food waste from Elizabethtown College each week, which is metered into the mix.

“We get more gas production with the addition of the food waste, equivalent to 20 to 30 kw per hour,” Mike says. That’s a bump of 10% to 15% more energy, pushing the digester’s gas production to about 90,000 cu. ft. per day.

The Brubakers occasionally take in other food wastes, such as cull egg yolks from a local hatchery and even food waste from a chocolate factory.

“When we add food waste from the college or egg yolks from the hatchery, it’s like rocket fuel for the digester,” Luke says. “The food is a complement to the cow manure.”

Plus, they receive tipping fees from all these venders. And they’ve sold carbon credits to NativeEnergy, Inc., which in turn sold them to the likes of the Ben & Jerry’s ice cream company and music legend Bon Jovi. Though not major dollars, it all adds to the revenue stream.

The Brubakers are looking into adding a second engine to generate even more power—especially if they can line up a consistent supply of quality food waste.

The benefits and innovation of the digester don’t stop with power production. The digested liquids, only 7% dry matter, are pushed through a Cri-Man screw press.

After separation, the remaining liquid is 3% solids and the separated solids are 35% dry matter.
The solids are dumped onto a concrete drying floor, which Mike designed. Under the floor run nine rows of 4" PVC, with a ½" hole drilled in the pipe and through the floor every 12". This creates a 1'x1' grid through which waste heat from the genset is pushed up through the floor and the digested solids. This extra heat and airflow removes another 5% of water from the solids, making it 40% dry matter and available for immediate rebedding.

Freestalls are bedded three times per week with the solids. Two neighboring farms purchase additional solids for bedding, along with local landscapers. In fact, the Brubakers have had to turn away potential customers because they simply don’t have enough bedding to meet the demand.

Waste heat from the system is also used to keep the digester at a constant 100°F. Plus, more than 1,000' of buried, insulated line runs waste heat from the digester complex to the milking center.

There, the waste heat is used to preheat water for the parlor and calf feeding prep room, heat the employee break room and run the pasteurizer for waste milk. “Normally, it creates enough heat for our pasteurizer and our 300-gal. waste milk bulk tank,” Tony says.

The batch pasteurizer holds milk at 146°F for 35 minutes, and then it’s stored at 141°F in the bulk tank until it’s cooled for feeding. (Above 140°F, bacteria will not regrow following the pasteurization process.)

Tony also retooled a radiator that allows him to circulate waste heat for the dairy’s towel drier, cutting propane use in half.

More recently, the Brubakers have tapped into solar power, placing hundreds of solar panels atop the south-facing roof of their new heifer barn.

The 720 panels cover some 10,000 sq. ft. of surface area, with each panel capable of producing 210 watts of electricity. At peak performance, they generate 130 kw per hour, enough electricity for about 130 homes.

Ninety-five percent of the electricity generated by the panels is pushed directly into PPL’s electrical grid. The remaining 5% is used to power lights, fans and the manure scraper in the 103'x312', six-row barn.

The Brubakers have also added a 26-kw solar system to their springer heifer barn. And Luke plans to start adding panels to the dry cow barn on the home farm.

Another eco-profit center, albeit a small one, is the nutrient trading agreement that Brubaker Farms has been able to develop with the Mount Joy Borough Authority.

The area surrounding Mount Joy drains into the Chesapeake Bay Watershed. For years, dairy operations in the region have been under the gun to eliminate nutrient runoff to surface waters. More recently, the state has clamped down on muni-cipal waste treatment facilities, recognizing that they add to nutrient loading of rivers and streams.

Pennsylvania allows these utilities to trade for nutrient credits with farmers who use runoff abatement practices above and beyond the normal conservation and nutrient management plan. In the Brubakers’ case, that entails no-till cropping and the use of cover crops.

The Brubakers negotiated with the Mount Joy Borough Authority to trade their nitrogen credits. It was the first such agreement in the state. “Our agreement is the real deal, because we’re reducing nitrogen losses right here in the same watershed as the Borough,” Mike says.

How many nutrient credits can be claimed depends on a laundry list of factors: crops grown, soil type, soil slope, proximity to surface water and manure application. When all is said and calculated, it usually amounts to 5 lb. to 10 lb. of nitrogen reduction. The most recent auction
valued those credits at $2.75 per pound of nitrogen.

While it’s not a six-figure revenue generator for the farm, it does remind local citizens that farms are an environmental asset. It’s also saving Mount Joy ratepayers $84,000 to $88,000 per year.
The savings come from the fact that removing the last bit of nitrogen from the municipal waste stream is extremely expensive, says Terry Kauffman, manager of the Mount Joy Borough Authority.

Physical treatment can take the nitrogen load from 20 parts per million (ppm) down to 10 ppm. But the Pennsylvania Department of Environmental Protection now requires a 6 ppm level. “Taking it down to 6 ppm is extremely expensive. Using nutrient credits from Brubaker Farms is where the real savings come,” Kauffman says.

Like most multigenerational farms, Brubaker Farms has grown from modest beginnings. Luke’s dad, Elam, bought the first parcel in 1929 and started with eight cows. In the 1960s, Luke and his brother Jim bought the herd, which had grown to all of 18 cows, and began growing the dairy oper-ation and acquiring land to support it.

The brothers grew the herd to 200 cows by the late 1980s. Jim opted out of the partnership in the early 1990s. Soon after, sons Mike and Tony joined Luke and together they expanded the herd to 400 cows. A few years later, they added another 200 cows and yet another 200 a few years after that.

Today the herd stands at 900 cows, with current facilities capable of maxing out at 940. The herd’s rolling herd average is 24,700 lb. on 2X milking and BST. The somatic cell count averages 150,000 cells/ml to 160,000 cells/ml annually, dipping to 120,000 in winter and peaking at 180,000 in summer.

The Brubakers also farm 1,000-plus acres in and around Mount Joy. Many of the parcels are irregularly shaped fields, tucked up against new housing developments. In fact, many of the homes rest on land that the Brubakers once farmed.

Because of their no-till cropping system, most manure is surface-applied with no incorporation. That could lead to nasty relations with neighbors. But here’s where the methane digester produces one last benefit: It reduces odor 75% to 90%, keeping neighbors happy and the Brubakers rolling on to their next innovation.


Talk about a win/win proposition. Elizabethtown College and Brubaker Farms have teamed up to take food waste from the college’s cafeterias to provide “rocket fuel” for the farm’s methane digester.

Each week, the college delivers 2,000 gal. to 3,000 gal. of food waste to the farm. Metered into the digester, the waste generates another 20 to 30 kw per hour, or 10% to 15% more electrical output.

E-town College, as it is known locally, has an enrollment of just 1,900 liberal arts students. But the college prepares some 14,000 meals per week for that student body, which can generate tons of both pre- and postconsumer food waste.

The preconsumer waste comes from excess cuttings from vegetable and fruit preparation. The postconsumer waste is all the uneaten scraps that would otherwise be flushed into the sewer.

Food waste is scraped into a grinding machine to produce a slurry. From there, 400' of tubing carries it to an extractor that dewaters the pulp, for an 80% water savings. The pulp is dropped into barrels for transport, while wastewater is pumped into a 1,000-gal. tank on a truck.

When full, the tank and barrels are transported to the Brubaker Farms digester. The entire process cuts waste hauling charges by half, says Eric Turzai, director of dining services for the college.

“A lot of colleges grind their food scraps and compost them, but none are recycling water and using food waste for electrical production to the extent we are,” he says.

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