Grazing at Solar Facilities

December 12, 2022
Solar Grazing in Action

Solar farms may not have looked much like farms in the past, but that is starting to change. Leasing land for solar development doesn’t have to mean shifting valuable acres of farmland to a space devoid of life and greenery. Fortunately, the same land can be used for both agriculture and solar arrays in a union known as agrivoltaics. For landowners who are interested in leasing land for solar projects but prefer to keep their land in agricultural production, agrivoltaics is a great option.

One exciting form of agrivoltaics is solar grazing, which enables landowners to keep their land in agricultural production while gaining income from solar energy. Four of the Mastodon Portfolio solar projects developed by OneEnergy in Wisconsin and Minnesota are currently being grazed by sheep. There are expansion plans to integrate sheep grazing at two additional projects being constructed in 2023. The graziers leading this work are Arlo Hark and Josephine Trople, who started Cannon Valley Graziers to achieve their goals of using sheep to provide land management services. Grazing can improve the quality of the land while also providing meat and fiber.

There are a lot of factors to consider when introducing livestock to a solar site. “Sheep are a natural fit,” said Arlo. “From an animal welfare standpoint, the sites are perfect. Shade is hard to come by in a lot of places we graze, which can be stressful on the animals while grazing in hot weather. The shade of the panels helps keep them cool, and the sheep do a great job of maintaining vegetation.”

Sheep are short enough that they can move freely beneath the panels without damaging them. In addition, replacing lawn mowers with sheep at solar sites lowers maintenance costs and emissions from mowing equipment. Sheep are also easy to move between pastures due to their small size, and they require less fencing than larger animals like cattle. In addition to the direct financial benefits, grazing improves the quality of the land itself. The prairie land that historically covered most of the Midwest is what made farmland in this area so productive. Years of plowing and harvesting have removed much of this rich topsoil, but new regenerative agricultural practices can help restore the soil.

In the past, prairies in the Midwest benefited from fires and grazing by bison and other large ruminants. Native prairie plants are adapted for fire, which stimulates growth and allows the plants to store more carbon in the soil. Since prescribed burning cannot be used to manage land at solar sites, sheep grazing provides a way to mimic the beneficial effects of traditional management and allows wildflowers and native grasses to grow back stronger. “Sheep are taking all of that carbon [from plants at the surface] and sending it back down [into the soil],” said Hark.

Rotational grazing is increasingly recognized as an important tool for conservation and can support plant diversity and reduce invasive species. Restoring grassland for pastures improves water quality and prevents stormwater runoff and erosion. Grazing improves soil quality by increasing microbial diversity, recycling nutrients, and sequestering more carbon into the soil. By stocking enough sheep to ensure that vegetation is evenly grazed and rotating the sheep consistently to allow vegetation to regenerate, Arlo and Josephine ensure that native plants benefit from grazing and are established for the long haul.

In some cases, the landowner or other members of the local community can use their own sheep to graze local solar sites. At Blue Prairie Solar in Black River Falls, WI, the landowner was able to graze their flock at the project site and receive payments for leasing the land as well as maintaining it. Similarly, at two of our projects currently in development, neighboring farmers are contributing by proposing to graze their sheep. We are excited to help bring together landowners, farmers, and other members of the community who can collaborate to reap the benefits of agrivoltaics.

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