If you’re American, the word Normandy probably makes you think of D-Day. In France, the region’s arguably just as famous for its cows. Normandy butter, cream and Camembert all start out as grass, and that grass stays green because, well, it rains a lot in Normandy.<\/p>\n
So it’s a bit of a jolt to hear that a pasture down in the hedgerow country south of the D-Day beaches went brown and stopped growing this summer. TSE, a French solar company, built a canopy of solar panels over part of a farm in Souleuvre-en-Bocage. In results published on September 17<\/a>, the company says the 14.8-acre open pasture it uses for comparison was “completely unproductive and dried out” from July on. The 7.4 acres under its 5,184 panels kept growing and were still green at the end of August.<\/p>\n The cows noticed too. From the first heat waves in May, the company says, the herd in the open field showed signs of stress while the herd under the canopy lay around calmly. On hot days, the open-field cows start heading back to the barn at 9:30 a.m. The shaded ones stay out until noon, their usual time to come in. So the cows in the shade get a normal morning, and the ones in the sun give up as much as two and a half hours of grazing.<\/p>\n To me, that barn schedule is the most interesting thing in the whole release, because it’s basically the cows voting with their feet.<\/p>\n Yoann Bizet, the farmer who works the land under the canopy, has a pretty simple answer. Once it gets past 68 degrees, he says, the herd in the open field just stands at the gate waiting to be let back into the barn, while the cows under the panels handle the heat a lot better. The company ran an almost word-for-word version of that line from him last fall, so I’d treat it as something he’s seen over more than one summer.<\/p>\n If you’re thinking 68 degrees sounds like a perfectly nice day, you’re right. For you, anyway. A cow runs a lot hotter. Its digestive system is basically a big fermentation tank, and the University of Minnesota Extension<\/a> points out that digestion and milk production both throw off heat, so a cow’s already warm before the sun gets involved. The extension service says mild heat stress generally kicks in for dairy cows around 72\u00b0F at 50 percent humidity, and high-producing cows can start feeling it at 65\u00b0F, even in a well-ventilated barn. Humidity drags that line lower, and Normandy isn’t exactly short on humidity.<\/p>\n These are dairy cows, too, and that raises the stakes. Back when TSE was raising money from local residents to build the canopy, it said the farmer had stopped putting his 130 milk cows out to pasture at all, because heat and long dry spells were hurting the grass, the cows’ comfort and how much milk they gave. The canopy was pitched as a way to get them back out on grass.<\/p>\n Now, before you picture some kind of magic grass machine, the company’s results from the previous two seasons say the shaded pasture and the open one grew roughly equal amounts of grass over a full year. The gap opens up when it gets dry. Shade cuts how much sun hits the ground and how much water bakes out of the soil, so the grass under the panels doesn’t brown out as fast. It’s why the strip of lawn in the shade of your house stays green in August after the rest of the yard has gone crispy.<\/p>\n The September release also covered a cornfield in eastern France we wrote about last month<\/a>, where corn under a canopy like this one got through the drought with 19.6 percent more dry matter than the open control plot.<\/p>\n Bizet’s said that during hot spells he was harvesting close to twice as much dry forage under the canopy as in the open, but I haven’t seen any tonnage published to back that up. The company’s put out a quality number, though. Forage cut under the canopy last year came in with 15 to 47 percent more protein than forage from the control pasture, with the gap depending on the time of year. More protein in the grass generally means less of it a dairy farmer has to buy in a bag. Oregon State saw something similar with sheep<\/a>, where the grass under its panels came in thinner but richer and the lambs put on just as much weight.<\/p>\n All the while, the canopy’s making electricity. Its panels add up to 2.9 megawatts, but that’s peak capacity, meaning what they can put out in full sun. Once you factor in nights and Normandy’s clouds, the company puts the site’s output at about 3.59 million kilowatt-hours a year, roughly a seventh of what it’d make running flat out around the clock. By the U.S. Energy Information Administration’s figure for what an average American household uses<\/a>, that’s still enough for about 330 homes.<\/p>\n The panels sit on motorized mounts that tilt them through the day, and they’re steered depending on the weather. So the shade doesn’t sit in fixed stripes from morning to night. It drifts across the pasture as the panels turn.<\/p>\n The lowest point of the structure is 16.4 feet off the ground, and each row is about 89 feet wide, so most farm machinery on the market can get underneath. That’s frankly a lot more headroom than any cow needs, but the haying equipment has to fit under there too. TSE says the posts holding it all up take about 0.5 percent of the ground, so nearly all of those 7.4 acres are still pasture.<\/p>\nSo why would a cow bail at 9:30 in the morning?<\/h2>\n
The grass under the panels hung on<\/h2>\n
There’s a power plant up there, too<\/h2>\n