West River Dairy, one of several dairy farms managed by Riverview LLP, houses 6,400 cows in the countryside near the rural community of Morris in western Minnesota. Built in 2004, West River originally relied on a “naturally vented” barn system, in which curtains along the walls could be rolled up to let air through the barn. With fan technology becoming more common in agricultural settings, however, Riverview recently installed a cross-ventilation fan system at its West River facility to pull air through the barns and milking parlor as needed.

Because milking is a “mission critical” operation for a dairy farm, Riverview installed a new generator to ensure that the fans – and the milking operations they support – would operate without interruption even during a power outage.

When West River was built, a pair of 600 kW generators provided backup power for the lighting and other equipment in the barns. Though emergency backup power wasn’t required by code, “when you’re milking at this scale, it’s a business requirement that crucial equipment is never without power,” said Jim Nieland, project manager for Riverview.

According to Nieland, Riverview’s goal in installing the cross-ventilation system at West River was to lower barn temperatures during the summer to keep the cows more comfortable and thereby minimize reductions in milk output. The existing generators couldn’t handle the extra load from the 240 cooling fans, so Riverview installed a new 750 kW generator to handle the 480hp fan load.

Cold-weather enclosure
Because of Minnesota’s harsh winter climate, the West River generator is housed in an all-weather enclosure with 1.5 inches of insulation that reduces heat loss. Although the generator set primarily supports summertime fan use, even in the winter some ventilation is needed in the barn.

Additional smaller loads also need to be operational throughout the year in the event of a power outage. Block heaters keep the engine warm even when it’s very cold outside. “If the temperature is -15°F and there’s a power outage, the generator is still warm enough to start and accept the load right away,” Nieland said.

In addition, the enclosure’s ventilation system includes intake and exhaust louvers that stay shut unless the unit is running, keeping out wind and snow.

Generator makes up for load shedding
Nieland estimates the new West River generator will run about 100 hours a year, primarily for load shedding with the local utility, Agralite Electrical Cooperative in Benson, Minnesota. By allowing Agralite to shed West River’s load during periods of peak power demand such as hot summer afternoons, “we get a much more attractive electrical rate,” Nieland said.

During load shedding, a radio signal from the utility starts the generator, which accepts the fan load once it has reached the proper voltage and frequency. With a 1,260-gallon fuel tank, the generator can meet any demands resulting from load shedding and/or power outages during a 24-hour period without refueling.

Whether the cause is load shedding or a summer thunderstorm, a loss of primary power at West River will have no impact on its thousands of cows, as they stay cool and productive with the help of a generator. PD

—Excerpts from MTU Onsite Energy

PHOTO
At West River Dairy, the 750 kW generator set features a diesel engine in an all-weather enclosure, ensuring that despite harsh winters and hot summers, ventilation fans will operate as needed to keep cows comfortable and milk production optimal. Photo courtesy of MTU Onsite Energy.