Solar Pastures

Several cooperatives have combined solar power with livestock grazing to employ “solar pastures,” which use the land under and around the solar panels for livestock grazing. The livestock cut mowing costs while providing a natural fertilizer for the soils.  This approach integrates solar power production with agriculture, diversifying the land use and providing added economic value to the community.

The most common livestock used for this purpose are sheep but other options are possible. Sheep are short enough not to block sunshine from most solar arrays, do not typically disturb equipment and enjoy the shade under panels on sunny days. They are not as likely as goats to harm the infrastructure.

In order to get the best outcome from this strategy, there needs to be early planning to pick the forage mix to be seeded for the type of livestock anticipated. The site operator will also need to make arrangements for site access with local farmers who contract to use the site and stock watering within the fence.

Likewise, a solar farm that will host livestock grazing should plan for the animals to minimize problems. One solar farm operator has reported that sheep grazing can bring unique challenges, but that might be avoided with planning. For example, sheep will rub up against posts and can trigger emergency shutdown buttons which can be prevented with caps. If they have reason to stampede, they may leap over obstructions and land on and break panels, which can be avoided by keeping structures off the ground. Sheep have been known to chew on exposed wires, so wires should not be accessible. Animals occasionally rub on (or even charge) workers who could be working on live, exposed wires. And, of course, animals defecate which can bring those familiar problems. While these reports have been rare, these livestock problems can be mitigated with proper planning.

Another benefit from sheep at solar farms is the enjoyment derived by the public when visiting or in news reports. Vernon Electric Cooperative in Wisconsin has different herds that forage at their solar arrays and have found it helps the project to integrate with the farming community.

Solar with Cattle

While sheep have been the predominant livestock used in solar pastures, new approaches show the possibility of harvesting the sun and providing pasture for grass-fed cattle on the same site. A new Vermont project demonstrates how to maintain agricultural use of the land with on-site solar.

When Greg Hathaway started his organic beef processing plant, Maple Ridge Meats, he sought to lower their power costs and increase sustainability with solar. Working with the Vermont Agency of Agriculture and a local renewable energy developer called Green Lantern Group, they pioneered a new style of solar array to be built on their pasture to partly power their operations.

Engineers designed a system with the panels raised higher from the ground, 8 feet at the lowest point, so the cattle can move beneath. The posts are about 30% longer above and below ground, with proper foundations to handle higher wind pressure. These are similar to carport solar arrays. The rest of the system is typical of solar farms.

On hot summer days the cattle seek relief from the sun, lined up in the shade of the panels.  It’s even become a local attraction for passersby who park along the country road. This approach could be used for cattle grazing elsewhere in the country, especially the Midwest and Great Plains.

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