As the expansion of green energy across the United States changes agricultural landscapes, power companies are encountering unplanned-for complications.
The Sherco Solar facility in Becker, Minnesota, is one of the sites battling with vegetation growth. Prairie plants are growing tall enough to cast shadows over the lowest row of panels, which means production is reduced.
Site managers managed to solve the problem without machinery or herbicides. Instead, they brought in 2,000 sheep plus a guard donkey. What did the combination of livestock do?
How nature is competing with solar power
The newly operational Sherco Solar project is the largest renewable installation in the Upper Midwest. It covers just under 5,000 acres of former farmland. It has a 710-megawatt capacity, relying on almost 1.7 million solar panels with cutting-edge automatic tracking systems.
The open Minnesota terrain created ideal conditions for weeds and prairie grasses, which grow tall and fast. The plants started blocking sunlight from reaching the bottom edges of the panels, triggering inverter shutoffs and reducing the power generated.
If installation operators use gas-powered lawnmowers to do the job, the dust covers the panels, blocking the light. For one thing, the machines struggle or fail in tight spaces. There’s also the danger of rocks being kicked up or an accidental bump, which can shatter the glass and take whole rows offline. The wiring could also be clipped.
Plus, running mowing machines burns fossil fuels, which defeats the green purpose.
The solar plant operators needed a solution for ground clearance that avoided all these risks.
Ecological complexity across open ground
Keeping thousands of fenced acres tidy involved more than cutting grass. Environmental teams had planted 35 native grass and wildflower species across the site to hold the topsoil in place and feed local bees and butterflies.
Fast-spreading weeds quickly began crowding out those native plants. The weeds built up thick layers of dead thatch that trapped moisture around panel posts and accelerated rust. Chemical weed killers were off the table because of strict local water protection rules.
At the same time, paying crew members to weed five thousand acres by hand was far too expensive. Leaving the growth unchecked invited fire risks during dry spells and threatened system performance.
The sheer size of the property also created a safety issue for livestock, as coyotes and other local predators regularly crossed the boundaries.
Facility managers needed a low-maintenance solution that could trim the growth and protect the herd across miles of open land, so sheep with lambs were brought in, reports Fresh Energy.
Targeted grazing and constant site protection
The sheep kept the invasive weeds down by eating the plants at ground level, while their hooves pressed into the soil to help native seeds take root. Because sheep graze low to the dirt without chewing on wires or jumping onto equipment, they keep sunlight hitting the panels without damaging the infrastructure. Their manure enriched the soil, and their natural grazing habits prevented dead grass from piling up.
At the same time, the guard donkey provided round-the-clock security against coyotes. Donkeys have a strong natural dislike for wild canines, staying alert through the night and aggressively chasing off predators before they can reach the flock.
Agrivoltaics is growing
Xcel Energy says this combination cleared the land, eliminated the need for mowers, and allowed native prairie species to thrive around the panels. By blending traditional farming practices with modern energy operations, the site shows how working lands can support both healthy soil and clean power generation.
Finding creative ways to manage large energy sites is becoming essential as power systems evolve, especially as facilities add massive long-duration battery installations to store excess solar power and keep electricity flowing during severe weather.
Read the whole thing?
Get the week's signal, not the noise
Our sharpest reporting on energy, climate and nature — free, once a week.
