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By Canary Media
Canary Media
CHRISTIANA, Tenn. — As sunlight fell between the gaps in flinty November clouds, I found myself impressed by the quietness of the lawn mowers in a Middle Tennessee solar field. Instead of the obnoxious roar of diesel engines, they just produced an occasional moo.
Six months ago, Tennessee’s largest solar developer, Silicon Ranch, channeled its nomenclature and brought cattle to this 3.25-megawatt solar project. The 15-member herd rotates among 15 paddocks marked out by simple electrical wire, munching Bermuda grass that grows in the shade of the panels, which sit on higher-than-usual steel piles. The cows seem amenable to the situation, judging by how plump they’ve become in that short time.
This is the first commercially viable utility-scale project combining solar and cattle farming in the U.S., according to Silicon Ranch (an earlier 2-MW project from AES sought to prove the concept in Massachusetts’ community solar market). If the model takes off, it could boost revenues for farmers while producing more clean, cheap electricity in regions that don’t have a lot of wide-open, unused spaces to develop. And it might remedy a major obstacle to ongoing solar growth.
The U.S. builds more solar installations than any other form of power plant these days. But the industry’s upstart success story is colliding with a bulwark of local opposition from communities that don’t like the idea of this relatively new technology taking over their landscapes. One way around that conflict is to use the same land for solar power and agriculture.
The solar industry already has adopted sheep grazing as a mainstream approach to cutting grass at project sites, while supporting a secondary market for domestic meat. Researchers have also found that grasses and some crops grow better in the shade of photovoltaic panels than in an open field. But the burgeoning “agrivoltaics” sector has almost entirely excluded one of the major pillars of American agriculture — cattle ranching — for the simple reason that rambunctious bovines could easily wreck the carefully calibrated solar panels.
“If you’re designing a solar facility that is suitable for cattle grazing, it generally requires more specific and unique design,” said Terry Jennings, principal team leader for renewable energy at the Electric Power Research Institute, a nonprofit that studies the electricity sector. That “adds cost to the overall project, which is challenging for utilities or electric power companies.” But he noted that research on this topic is still pretty new, and a lot of uncertainty remains around “how cows really interact with the solar panels.”
To go mainstream, and help meet America’s soaring demand for electricity with more carbon-free generation, cattle-friendly solar needs to appeal to large-scale developers who rigorously maximize megawatt-hours generated per acre while minimizing cost.
In the countryside about 45 minutes southeast of its Nashville headquarters, Silicon Ranch has found that the commonly understood challenges for cattle grazing alongside solar were a little overblown.
“I thought it would work — I just didn’t think it would work this well,” said Loran Shallenberger, a longtime farmer who now runs Silicon Ranch’s Regenerative Energy and Agrivoltaics division.
Shallenberger’s team designed a system to withstand the presence of cows at a minimal cost premium. Even for this first utility-scale installation, they held the cost of fortifying the arrays to just 3% over the standard design, Shallenberger said, and nonetheless sold the power to local utility Middle Tennessee Electric for cheaper than the wholesale rates it was paying to the Tennessee Valley Authority.
As far as climate solutions go, this doesn’t deal with the immense greenhouse gas emissions that arise from cow burps and farts; many climate activists want to phase out commercial cattle entirely for that reason, or for animal welfare motivations. But as long as cattle production is widespread in the U.S., doubling-booking pastureland for solar production could produce more clean energy in a space-constrained world.
Clever innovations in solar rarely go anywhere. Entrepreneurs might drive a news cycle with “solar freakin’ roadways” or solar roof tiles, but to succeed in this market requires ruthless efficiency and streamlined repeatability. Throwing a herd of cattle into the mix does not, at first glance, conform to that industrial mantra.
Shallenberger had ready answers for my journalistic skepticism.
On the hardware side, after studying the matter with a grant from the Department of Energy, Silicon Ranch resisted the urge to build towering solar supports, which would require even more steel underground to ensure stability. Instead, the company developed and patented a system dubbed CattleTracker: mildly elevated steel piles with customized controls for the tracker, supplied by NextPower.
Trackers typically rotate throughout the day to eke every last bit of electricity out of the sun’s arc. At the Christiana solar farm, the trackers in that active paddock go into “graze mode,” which limits their rotation from a maximum tilt of 60 degrees from the ground to 20 or 30 degrees — so the lower edges of the panels remain above the animals’ heads. At a regular solar farm, the low end of a fully tilted solar panel is 24 inches off the ground, but I could walk beneath the CattleTracker system with just a little ducking.
The cattle do their part to make this work.
Shallenberger bought a herd of Murray Greys, an Australian breed that “are widely regarded as having uniformly calm dispositions” — the kind of cattle you could grab a beer with. That docility makes them less inclined to damage solar equipment or charge at a technician who’s checking out the site. They helpfully don’t grow very tall, and they have “consistently good carcasses,” industry lingo for qualities like high meat-to-bone ratio and well-marbled steaks. Plus, Murray Greys can fatten up on grass alone, so they could be ready for market in 18 to 24 months without a stop at a feedlot.
I saw one specimen scratch its head against a steel pile, but none of the herd could reach the sensitive equipment. The concern is that if the cows hit the solar panels hard enough, they could cause microfractures that over time diminish electricity production. Shallenberger said that if he were building the site now, he’d drop the pile height by 6 or 12 inches, because it turned out to be a little overbuilt.
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The nationwide cattle inventory has fallen to its lowest point in 75 years, as prolonged drought hits the vast arid ranchland of the Western states. Rising beef prices have incentivized ranchers in wetter parts of the country to get into the game. Tennessee, Shallenberger told me, is already one of the biggest cattle states east of the Mississippi.
Abundant local water sources aside, this was a particularly harsh summer in Tennessee.
“If you’ve ever been out in a cattle ranch and there’s a single tree out in the middle of the pasture, they’re going to congregate around it for shade,” Silicon Ranch Chief Commercial Officer Matt Beasley said from his office in Nashville. Consequently, the cattle perform better under the shelter of solar arrays than in the open range, he noted.
The solar canopy also protects the grasses, keeping them green and dewy, even as nearby fields blanch and crisp in the sunlight. Shallanberger rotates the herd every few days, a key tenet of regenerative farming philosophy, so they munch on fresh grass while the rest of the field grows back. They move through all 15 paddocks in about 45 days; if the site relied on mechanical mowers, they’d trim every 45 days, too.
That cycle also keeps the grasses from shading the panels or messing with the machinery.
Vegetation management is one of the most significant costs for solar plant maintenance in the Southeast, Shallenberger said. In the first six months, the cattle took care of about 75% of the mowing — he had to bring in conventional equipment for some woody weeds that the cattle don’t care for. Once the pasture is more established, the herd could handle up to 95% of the site’s mowing needs.
“The team had this anthem: It’s got to be good for the land, good for the animal, and good for the solar,” Beasley said. “If it’s not good for all three, we’re not doing it.”
CattleTracker does reduce solar production slightly, given the limited tilt on the small subset of panels in the active paddock. Silicon Ranch is happy to trade that loss for the drastic reduction in major operational costs. The herd doesn’t need the hands-on attention that sheep require; a camera watches to ensure they have enough water, and an attendant visits twice a week to move paddocks and perform a wellness check.
Cattle-friendly solar’s bucolic charm is undeniable, but its impact hinges on widespread adoption.
“The hope is that it can be mainstream,” Shallenberger said. He pointed out that it doesn’t take more labor to open a paddock gate for 100 animals as opposed to 10, so the operational cost savings should scale favorably for larger solar projects.
Silicon Ranch expanded its use of sheep for pruning solar fields after its executives got to know Will Harris, a leader in the regenerative farming movement whose land neighbors a Silicon Ranch project in southwest Georgia. The developer acquired 400 ewes in 2022 and has grown the herd to 5,000 through selective breeding. Silicon Ranch also partners with 14 sheep-farming families across six states for managed grazing.
“In the back of our minds has always been, Can we replicate this with cattle?” said Beasley. Now, the team is scouring its development portfolio for sites to deploy CattleTracker. Silicon Ranch builds projects up to 300 MW, and hasn’t found any reason that cattle couldn’t graze at that scale.
“It’s not too long down the road that you’ll be able to try a beef burger or a steak raised on Silicon Ranch land,” Beasley said.
The company’s agrarian activities play a strategic role beyond diversifying revenue streams. Local opposition to solar projects has become “the most existential threat to deploying solar projects in this country,” Beasley said. Wild theories about solar keep spreading on social media, and the popular revolt against AI data center construction can spill over to resisting the renewable energy source, even though rows of panels don’t come with the same downsides, like immense water use, inescapable droning noise, and fossil-fueled generator fumes.
Beasley said that approaching rural communities as an authentic agribusiness — one committed to long-term stewardship of the land it owns — helps address a lot of their concerns.
“We’re not taking land out of ag production. In fact, most of the land that we’re buying wasn’t in ag production before, and we’re going to put it into ag production,” he said. “We’re going to raise grass-fed meats, and we’re going to hire local shepherds or partner with local farming families.”
The cows will release methane, making the site a bigger greenhouse gas emitter than it would be without the herd. But journalist Michael Grunwald, who literally wrote the book on how to feed the earth without exacerbating climate change, said the cattle-solar approach is a good example of the “sustainable intensification” that he wants to see more of.
“This acre that was already making a lot of energy, now it’s also making some beef,” he explained. “Somewhere else you can take a beef acre and make it carbon storage or something.”
At scale, this dual use could produce much-needed food while easing pressure to convert other landscapes for cattle grazing. And half the ag land in the U.S. is dedicated to growing beef, Grunwald added. That leaves the hypothetical cattle-voltaics market plenty of room to grow.
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Julian Spector is a senior reporter at Canary Media. He reports on batteries, long-duration energy storage, low-carbon hydrogen, and clean energy breakthroughs around the world.
Electrification
Data centers
Clean energy manufacturing
Politics
U.S. regions
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