Cows Energize Environmentally Friendly Barn

We're used to getting milk, meat and even leather from cows. But who knew you could tap the heat from their milk, breath and manure to reap significant energy savings? These cow outputs are being harnessed to help power a unique new dairy barn near Sylvan Lake in central Alberta.

"We realized that natural gas wasn't getting any cheaper," says Justin Bell, part owner in the farm. "So we went for an energy-efficient design when building our new barn. The upfront cost is higher, but we will see return on our investment in about four years."

It's not your usual energy-efficiency design that Luuke van Wouw of Terra-Therm Systems Inc. came up with. The cow manure, for example, descends into a large trench colder than the manure. The heat from the waste is transferred to a heat pump, amplified and transported to a hot water tank, which provides water hot enough to flush the milking lines by dissolving the fat particles.

Additional energy for the hot water tank is extracted from the cow's milk through a heat exchanger; this process also cools the milk to storage temperature. As well, a fan coil captures, chills, and dehumidifies warm, moist air from the cows' breath.

It all started when Bell visited his cousin's house and met van Wouw, who was installing a geothermal heating system - capturing the ground's warmth to produce heat - for the family swimming pool. "Justin asked me if something similar could be designed to power their barn, and the wheels in my head started to turn," says van Wouw.

The cows aren't the only source of heat in the new dairy barn. Van Wouw also installed a geothermal heating loop for backup power in emergencies and air conditioning in the summer. "The summer will be a breeze for the animals since we can transfer the heat into the ground," he says.

The energy-efficient design has also resulted in a cleaner, odour-free barn. "Since the waste from the animals is swept away, so is the odour," says Bell. "If someone was blindfolded, they would have no idea they were in a building full of cows." Chilling the manure also slows the bacteria process, while dehumidifying the air nearly eliminates ammonia, offers improved visibility, gets rid of mildew and leaves a warm dry floor.

As an added bonus, the more contented cows are producing more milk. Says Bell: "This barn has surpassed our expectations in so many ways."

Not surprisingly, this unique dairy barn has stirred considerable interest in the agricultural community and beyond. "I think that this technology is the wave of the future in agriculture," says van Wouw. "This kind of a design offers increased production, cost savings and lowers environmental improvements. It's nice to see farmers benefiting from energy efficiency."