Anyone who’s spent time around dairy cattle will tell you a cow treats anything new in her pasture the same way. She licks it, and then she rubs on it. Fence post, water tank, the side of your truck, it doesn’t matter. So when a University of Minnesota researcher decided to put solar panels in a cow pasture, the first question wasn’t about electricity. It was how you’d keep a very large, very curious animal from wrecking the glass.<\/p>\n
Brad Heins, who runs the dairy research at the university’s West Central Research and Outreach Center<\/a> in Morris, settled it with a tape measure. He found the tallest cow in the herd, worked out how high she could reach with her tongue, and set the bottom edge of the panels at 8 feet. He’s since admitted that was probably overkill. But the first array went up in 2017, and apart from a few days of the herd licking the panels and rubbing on the poles, the cows have pretty much left it alone.<\/p>\n Which, it turns out, is the question every farmer asks him first.<\/p>\n Heins says he gets an email about panel damage from a farmer at least five times a week. Agrivoltaics is the catch-all term for getting a piece of land to grow something and make electricity at the same time, and here in the US what we mostly get is sheep grazing between rows of panels, because sheep are short and don’t lean on things. When Morris started, Heins says, Minnesota already had sheep grazing under panels. Cows, no.<\/p>\n That first system was small. Thirty kilowatts, split into two banks of 15, with the steel posts set in concrete 6 feet down. Heins has said they “probably built it hurricane-strength,” and the university put the cost at about $90,000, with the extra height adding very little of that. The actual experiment ran in the summer of 2019, and it was about as simple as a cow study gets: 24 crossbred cows, 12 with access to the panels and 12 without, for 28 days.<\/p>\n The two groups gave just as much milk as each other. The shaded cows were dirtier, which the researchers put down to moisture and manure building up under the panels. The difference that mattered was in the cows themselves. The cows out in the sun breathed 78 times a minute, against 66 for the cows in the shade, and ran a full degree Fahrenheit hotter.<\/p>\n One degree doesn’t sound like much. A cow’s normal body temperature sits somewhere around 101.5\u00b0F, and one more degree is the kind of change a vet would notice. Heins, asked about it at the field’s dedication, didn’t hedge. “Actually that 1 degree is a big difference,” he told Agweek<\/a>, and he tied it to milk production, heifer growth and general stress on the animals.<\/p>\n So if you’re a dairy farmer expecting a milk bump from the shade, there wasn’t one in 28 days, and I’d be a little skeptical of anyone selling you panels on that basis. What you’re buying is a herd that’s less heat-stressed. Whether that turns into milk over a whole summer is what the longer research is supposed to tell us.<\/p>\n The next array came in 2021, a 240-kilowatt array big enough to shade 200 to 250 cows at a time. This time the poles went 6 feet into the ground without any concrete. And here’s a detail that I think gets lost in most of the coverage: the cows don’t live under the panels. The paddocks at Morris are run for grass, not for shade, so the herd only moves into the solar paddock when the grass there’s ready to graze. In the 2023 season that worked out to about 10 days of shade all summer.<\/p>\n That summer was a dry one in western Minnesota, and Heins noticed the grass under the panels came back faster after grazing than the grass in the open paddocks. Of the roughly 25 plant mixes the center has tried, orchard grass, meadow fescue and red clover have done best under the glass. A French solar company saw something similar on a Normandy dairy pasture this year<\/a>, where the open field browned out in July and the shaded one stayed green through August. Less sun on the ground means less water baking out of the soil, and in a dry year that’s the difference between a second grazing and bare dirt.<\/p>\n I’d be careful reading too much into one dry summer, and Heins hasn’t published a yield number for the grass that I can find. But the direction matches what’s showing up in other pastures.<\/p>\n The field that put Morris on the map is the 500-kilowatt one, dedicated on September 6, 2024, and reported by Agweek as likely the biggest cow-and-solar pasture in the Midwest. Its electricity goes to the University of Minnesota Morris campus, which says it runs carbon-neutral, and its shade goes to the research dairy’s cows.<\/p>\n Getting it built took some arguing. Bryan Herrmann, the campus’s vice chancellor for finance and facilities, said some contractors told the university that panels 8 feet off the ground simply wouldn’t work. A solar contractor from Hudson, Wisconsin, Energy Concepts, took the job and hammered the steel posts 8 feet down into the dirt, no concrete footings, then hung the panels with their bottom edge 8 feet up. No concrete also means that when the panels wear out, you can pull the posts and get the pasture back.<\/p>\n Does a post with nothing holding it but dirt actually stay put? Apparently so. A storm came through with 80-mph winds, damaged trees and buildings in the area, and left the array alone. The company’s president put it down to structural engineering, which is a fairly modest way of saying they’d done the math on the wind load. The panels are angled and spaced for electricity, with one row never shading the next even under the low winter sun, and the shade for the cows is a side effect of that.<\/p>\n The field cost about $731,000, with $452,000 of that from the Legislative-Citizen Commission on Minnesota Resources, which mostly runs on state lottery money. Another 280 kilowatts of bifacial panels were going in at the research center that summer. Bifacial panels catch light bouncing off the ground on their undersides as well as on top, which in a state that spends a good chunk of the year under snow is a pretty neat trick.<\/p>\n One thing I couldn’t find anywhere is how many panels are in that 500-kilowatt field. Agweek went with “hundreds,” and the university’s never published a count, which is a slightly odd thing to leave out of a dedication ceremony.<\/p>\n Here’s where I think the research gets interesting for anyone who isn’t a university. Fixed panels on 8-foot poles are a luxury. The solar industry mostly builds single-axis trackers now, panels that tilt through the day to follow the sun, and when a tracker tilts, one edge drops into cow range. Raising the whole thing costs money a developer would rather not spend. You can get around the reach problem by standing the panels on edge instead, which is what Rutgers did in a New Jersey cattle pasture<\/a>, but then you give up most of the shade at midday, which is when a cow actually wants it.<\/p>\n So the center’s asked the state for $1,443,000 to build a roughly 255-kilowatt tracker array in an organic pasture and split it three ways: one section left exactly as a developer would build it, one with electric fence wire on brackets along the panel edges, and one raised out of reach on longer poles. The center’s proposal<\/a> puts 96 Holstein and crossbred cows into four groups of 24 and fits them with GPS collars, at about $400 a cow, so the grazing boundary can be moved around on a screen to keep them off the tilted edges while still letting them get to the shade.<\/p>\n The paperwork’s got the array layout done by October 31, 2026, and the panels installed by June 30, 2027. I couldn’t tell from the commission’s website whether the money’s been approved, so treat those as a plan, not a schedule.<\/p>\n The herd under the existing panels isn’t waiting on any of that. Heins told Sahan Journal<\/a>, in a story the Associated Press distributed on September 23, 2026, that about 275 cows now graze between the rows of the 500-kilowatt array, eight years into the project, and that “it’s garnered a lot of interest in Minnesota and around the world.”<\/p>\n","protected":false},"excerpt":{"rendered":" Anyone who’s spent time around dairy cattle will tell you a cow treats anything new in her pasture the same … <\/p>\nTwelve cows in the shade, twelve in the sun<\/h2>\n
The grass held up in a dry year<\/h2>\n
Then they built a much bigger one<\/h2>\n
Now they want to try it without the tall poles<\/h2>\n