Every Farm Has Unique Energy Use Footprint

Each dairy farm uses power differently, but ventilation and lighting often are top users. ( Farm Journal, Inc. )

The anthropologist Margaret Mead liked to point out the obvious: “Always remember that you are absolutely unique. Just like everyone else.”

No truer words could be said about dairy farms—and their use of energy. As a result, finding ways to enhance efficiency and/or reduce energy and electrical use will be specific to your farm, says Brad Heins, a dairy specialist with the University of Minnesota’s West Central Research and Outreach Center at Morris.

“Everybody is different, and every farm has its own characteristics when it comes to energy use,” he says.

The Morris Experiment Station has 200 cows that graze whenever the grass is growing on the western Minnesota prairie. As such, only 7% of total energy use is needed for barn ventilation in the non-grazing months. The station’s major energy use comes in heating the milking parlor (31%), heating water for cleaning (22%) and cooling milk (11%).

That’s in contrast to conventional dairies with cows housed year-round in freestalls. But even here, use varies depending on how the farms are managed. Over the past year, Heins and his graduate students have been monitoring energy use on four conventional dairies in west central Minnesota. They include:

• Farm A.

                9,500 cows

                Cross-ventilated barn

                106-stall rotary parlor

                Build in 2017.

                Ships 12 tankers of milk per day

•Farm B.

                300 cows

                Naturally-ventilated barn

                Six robotic milkers since 2016.

• Farm C.

                200 cows

                Naturally-ventilated barn

                Double-eight herringbone parlor

                20% of milk diverted to on-farm cheese making plant

• Farm D.

                400 cows

                Naturally-ventilated barn

                Double-eight herringbone parlor

                Manure composting with a drum system

                Transitioning to robotic milking

To collect energy use, data logger were installed within each dairy’s circuit panel so they could monitor nearly 300 electrical lodes on the farms.

Heins and his research crew are still analyzing data after a year’s worth of collection, but already trends are pretty clear:

For Farm A, ventilation fans in the huge cross-vent barn use the majority of power in the spring, summer and fall. In winter and spring the farm’s “veterinary room,” which is used for calving cows and treatments, requires a lot of energy simply to keep the area warm.

For Farm B, ventilation fans take up the majority of the energy in June through September, but keeping the robotic milking rooms warm are the big energy users in winter and early spring.

For Farm C, ventilation fans take up nearly half the power usage in July, August and September. But heating water for cleaning equipment in both the parlor and the cheese manufacturing area accounts for 30 to 40% of electrical use year-round.

For Farm D, ventilation of the barn is the biggest user in July, August and September. Lighting accounts for about 20% of electrical use year-round. But the drum composter, heated with electricity, is using 25% or more of the power purchased each month.

The take-home message, says Heins, is that each dairy is faced with unique energy challenges. “But consumers and market chains will like continue to demand dairy farms reduce their carbon foot prints and be more environmentally stable,” he says.

He recommends that to reduce energy use, farms focus on their areas of highest energy demand. For many dairies, that likely will be ventilation fans. “Proper sizing, settings and maintenance of fans can save 15%,” he says.

Also look to lighting. Converting to LEDs and using timers and photoelectric sensors will help.

As a side note, Heins says most all larger dairies have emergency power, and many of the engines that power these generators have block heaters to ensure they start when needed. On one of the dairies studied, the block heater was faulty, constantly drawing excess power.

Studies on large commercial hog farms has also shown faulty block heaters can be a problem. So checking and replacing these heaters on a regular maintenance schedule might be warranted, he says.

 

 

 

 
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