Oberlin sheep grazing team to reduce solar mowing costs by more than 44%

Just as Oberlin College students were leaving campus this past week to enjoy their summer recess, a new group was entering campus by farm truck. On May 24, a class of 70 ewes from the Old Slate Farm in Knox County, Ohio, showed up on campus to begin chomping away at weeds, grass and other edible vegetation at the college’s 2.3 MW solar field.

Some 70 Katahdin breed sheep were dropped off on campus this week at Oberlin’s 10-acre fenced-in North Field. There they will graze through mid-June, stomping grass and weeding the solar field in a move aimed at alleviating the need for costly operations and maintenance involved with a commercial lawnmowing crew, according to a report by the school’s Conservatory institute.

Additional sheep drops this summer will bring the total number of grazers at Oberlin’s on-site solar facility to between 150 and 200 heads of sheep.

The sheep will be delivered to the college’s solar field three times per year over the spring, summer, and fall season. A form of agrivoltaics, where land is used for both agriculture and energy generation, the sheep’s handiwork will reduce Oberlin’s emissions from fossil fuel. It is also expected to reduce regular damage to equipment that results from mowing a rough terrain.

Oberlin signed an agreement with Old Slate Farm in April to begin deploying the sheep grazers before summer.

The college reportedly has spent $15,000 to $30,000 per year on mowing expenses on the 2.3 MW solar field, while the use of up to 200 sheep will reduce its O&M costs on the solar field to about $6,600 per year, Oberlin campus energy and resource manager Joel Baetens told the Oberlin Review.

The solar grazing approach will aid the college in achieving goals of becoming carbon neutral by 2025, a goal the school set in 2006. The college was one of the first U.S. university systems to come out with a campus-wide environmental and sustainability framework under the Carbon Commitment program (formerly the American College and University Presidents’ Climate Commitment).

Over the following years, the college installed additional solar arrays as well, with a 59 kW rooftop array on the Adam Joseph Lewis Center for Environmental Studies and a 101 kW car canopy system on a parking garage.

The Midwest college didn’t stop at just shy of 2.5 MW of solar installations though. In the Spring of 2021, the college announced a $140 million geothermal energy project aimed at drilling 1,100 geothermal wells at its South Campus buildings. The geothermal wells will reduce energy, heating and cooling costs, including decades-old cooling infrastructure that costs the school about $1 million per year in excess energy costs.

The project will convert the college’s decades-old boiler plant with geothermal energy, using thermal energy equipment as a natural gas backup system, in addition to the geothermal wells across the campus. The geothermal installations are expected to be deployed by 2025 under partnership with Ever-Green Energy, a St. Paul, Minn.-based district energy company.

“Obies care deeply about our collective impact on the environment,” said Meghan Riesterer, assistant vice president for campus energy and sustainability, about the geothermal project. “This is a collaborative solution developed by representatives from across our community, together with experts.”

Old Slate Farm is a cut flower and Katahdin sheep farm in Mount Vernon, Ohio. In addition to flower arrangements and raising sheep, the midwestern farm also hosts weddings on its large farmstead in central Ohio.