This article was #22 of the Top 25 most well-read articles on in 2012. to jump to the article. It was published in the January 21, 2012 issue. Click here for the full list of the Top 25. In addition to milk, cows also produce a fair amount of methane. Dairies across the country are developing new ways to utilize that byproduct of milk production. One instance is a project under way at Fair Oaks in Indiana to use biogas from its anaerobic digesters to power a fleet of milk trucks operated by Ruan Transport Corp.

Q. The article mentions this project could be a model for the rest of the industry; has Ruan converted any of its other fleets to compressed natural gas?

The Fair Oaks-Ruan fleet is the only compressed natural gas (CNG) fleet Ruan operates today. Ruan has a long tradition of seeking and implementing strategic fuel conservation measures, which not only controls costs but also helps protect the environment.

The company continually investigates new, sustainable fuel options. Ruan is currently evaluating specific fleets for conversion to natural gas in 2013 and has begun offering natural gas-powered equipment as a clean fuel alternative for its customers.

In addition, Ruan utilizes a variety of environmentally friendly strategies, including idle reduction, aerodynamic skirting, cab extenders, auxiliary power unit (APU) usage, low-viscosity lubricants, reduced highway speeds, lightweight equipment, paperless technologies and processes and successful driver training designed with an emphasis on maintenance and fuel consumption.


Ruan also monitors the performance of its drivers and equipment with electronic on-board recorder (EOBR).

Ruan is a long-standing partner of SmartWay, a collaboration between the Environmental Protection Agency (EPA) and the freight industry designed to increase energy efficiency while significantly reducing greenhouse gases and air pollution.

Ruan was recently honored with a SmartWay Excellence Award from the EPA as a true industry leader in freight supply chain environmental performance and energy efficiency. Ruan was one of 40 companies – representing fewer than 1 percent of SmartWay’s 3,000 partners – to receive this distinction.
—Tara Meier, VP Marketing and Corporate Communications, Ruan Transportation Management Systems

Like many U.S. dairy farms with digesters, Fair Oaks Farms harnesses the energy in cow manure to produce electricity.

The group of 10 dairy farms near Fair Oaks, Indiana, will soon go a step further by using biogas from its anaerobic digesters to power a fleet of milk trucks.

The farms have already begun transporting milk with 42 new trucks powered by compressed natural gas. The full transition to biomethane, a clean, renewable fuel ready for the natural gas pipeline, is expected to be complete by spring 2012.

Ruan Transport Corp. picks up about 53 loads of milk per day from Fair Oaks member farms for delivery to three processing plants in Indiana, Kentucky and Tennessee.

With 6,000 gallons of milk in each load, Ruan Transport will haul approximately 90 million gallons of milk for Fair Oaks each year using the new natural gas-powered trucks.

By switching their truck fleet to natural gas, Fair Oaks farmers are displacing more than 1.5 million gallons of diesel per year and reducing exhaust emissions by an estimated 40 percent.

The project is expected to be the largest long-haul truck fleet powered by renewable energy in the U.S.

Switching from fossil fuels to a renewable transportation fuel that’s made from cow manure makes sense environmentally and economically, says Mark Stoermann, project manager at Fair Oaks Farms.

“There are several advantages for the dairy producer,” Stoermann says. “Number one, it’s another value-added revenue stream, taking what had been seen as a waste and a liability and converting it to something of value.”

Another big advantage is that natural gas is much cheaper than diesel.

“Right now diesel fuel is high, and there are not any projections for it to drop incredibly low,” Stoermann says. “There’s an opportunity for us as an industry to lower some costs on one side and to make a very, very important impact on the use of foreign fuels.”

The project is being completed in two stages.

The first stage, already completed, included the purchase of 42 new trucks powered by nine-liter Cummins engines designed to run on compressed natural gas. It also included the construction of two new CNG fueling stations in cooperation with Clean Energy.

The second stage, slated for completion in spring 2012, will include the installation of gas upgrading equipment, most of which must be imported from New Zealand.

The equipment will have to be integrated into the existing anaerobic digester system and a pipeline completed.

Right now there are few natural gas fueling stations in the U.S., primarily because there are relatively few vehicles outside of some city bus systems and waste-disposal companies that use the fuel.

But that could change if more milk hauling fleets switch to natural gas, Stoermann says.

“By having dedicated fleets with 365-day operations running through these fueling stations, you can start to expand that infrastructure,” he says.

The Fair Oaks project could become a model for the rest of the industry. But industry officials acknowledge there are some big hurdles – some of them regulatory and some economic – to overcome before cow-powered milk trucks come into widespread use.

In 2009, Hilarides Dairy near Lindsay, California, became the first dairy in the U.S. to run milk trucks on “cow power.” Two diesel trucks were converted to run on biomethane produced from an anaerobic digester.

Long-range plans called for expansion of the project with development of a biogas-to-biomethane upgrading plant and refueling station at Hilmar Cheese.

Supporters envisioned a large fleet of biomethane-powered trucks delivering milk to the cheese plant every day.

It never happened.

“It was not economically feasible,” says Michael Marsh, CEO of Western United Dairymen, one of several groups involved in the project.

Marsh says it’s disappointing the project didn’t work out. Even with some federal grant funding, it was just too expensive.

“For that kind of project you might be looking at $8 to $10 million,” he says.

“Unless there is a way for it to pencil out, dairy producers won’t go in. It has to pay for itself.”

Norma McDonald, North America sales manager for Organic Waste Systems Inc., says biomethane usage as a transportation fuel could increase with more favorable tax credits.

The existing tax code requires the production of electricity to quality for biogas tax credits.

Her group has proposed legislation that would expand eligible uses to transportation fuel.

“The other thing I think will spur development is that a number of companies are now selling conversion kits to allow engines to run on either conventional fuel or biomethane,” McDonald says.

Drivers of such flex fuel rigs don’t have to worry about running out of biomethane on a long run. They can just flip a switch and run on diesel if they need to.

More affordable equipment, whether it’s engine conversion kits or biogas upgrade equipment, would also help boost the use of biomethane as a transportation fuel, McDonald says.

More efficient engines would also help, according to Carol and Eddie Sturman of Sturman Industries.

The Sturmans have developed a camless system using digital valves, hydraulics and microprocessor controls to improve engine efficiency.

“It can be integrated into brand-new engines or we’re currently designing a fairly simple way to do a retrofit of an engine,” says Carol Sturman.

The system can tolerate less highly refined fuels and has the ability to control the combustion temperature and air flow.

Regardless of the fuel put into the engine, it has the intelligence and flexibility to operate at the “sweet spot,” she says.

The Sturmans believe people shouldn’t be forced to design fuels to fit into existing engines. It should be the other way around.

“We should have a smart engine that could accommodate any liquid fuel or any gaseous fuel, or it could even be designed to do both,” Carol Sturman says.

The technology is there and it should be a boost to the biogas industry, she says. PD

Wilkins is a freelance writer based in Twin Falls, Idaho.