If a solar farm is built in Pulvers Corners by Carson Power, could sheep one day graze under the panels? Could wildflowers attract honeybees and monarch butterflies?
Debate over the solar proposal, set for public comment at a special meeting on June 10 at the community room over the Pine Plains Free Library, has focused primarily on visibility of the panels and fear among local homeowners about potential property depreciation. But there are also concerns over the fate of the land under the panels.
It’s part of a wider regional, national, and indeed international discussion about the dual priorities of food and energy. One potential solution is agrovoltaics, or dual use of land.
“As more solar projects get built, land-use competition is going to be a challenge,” said Max Zhang, a professor of mechanical engineering who studies solar panels and agriculture at Cornell University in Ithaca, New York. “It’s a legitimate concern in the agricultural community. How can we preserve land as a source for food as well as for renewable energy?”
According to the solar guidebook prepared for local governments by New York state’s Energy Research and Development Authority, solar projects “can be designed with co-use in mind [for]…livestock grazing, beekeeping, cultivation of certain crops, or planting of pollinator-friendly vegetation under and around the panels.”
The proposal to build a 43-acre solar farm in Pulvers Corners on 172 acres (about 50 or 60 of which would remain in crops such as soybean and corn) does not currently include any plan for grazing, according to Andrew Gordon, a senior project manager with Carson Power who travels frequently to Pine Plains.
Instead, current plans envision maintaining the solar field as a meadow habitat, Gordon said. The land would be planted with a “native mix of grasses and wildlife species, including milkweed, which is food for monarch butterflies,” he said. He added that the site would be mowed between two and four times a year – to keep grass and other plants from growing so high they would shade the panels.
A 7-foot “wildlife-friendly” fence composed of wooden posts and wire fencing, with a 4-inch gap at the bottom, would “let rodents and rabbits and other small species underneath so they can get to the meadow, but keep out larger animals like deer,” Gordon added.
Some environmentalists, however, have questioned whether some of the plants envisioned for Carson’s proposed meadow are appropriate for the Pulvers Corners site.
In a report produced by Hudsonia, a nonprofit institute in Annandale, New York, Executive Director and ecologist Erik Kiviat stated that “the species list for seeding is inappropriate and contains numerous plant species not native to the Hudson Valley,” adding that the New York Flora Association plant atlas should be the guide for appropriate seeding.
The report also recommends that mowing should take place no more than one time a year, and only after September, once the insect season has ended. “Desirable herbaceous plants, including forbs with showy flowers for nectar and pollen, and certain sedges and grasses for butterfly and moth larval hosts, will grow and flower in spring and summer,” the report said. “A small mower and a hand-operated trimmer can be used to selectively cut plants (if any) that begin to overgrow the lower edges of panels.”
The report was prepared for Grant & Lyons LLP, a law firm hired by a group of Pine Plains residents who live near the proposed solar farm project and are opposed to its construction.
When asked about the Hudsonia concerns over mowing frequency, Gordon said that decision would be up to the teams hired by Carson to manage operations and maintenance, adding simply, “when the grass gets too high, it gets cut.” Regarding the seed mix, he reiterated that “we want to plant something native, that has local benefits, such as pollinator-friendly species, and we’ve intentionally included milkweed to the benefit of monarch butterflies.” He suggested that more attention be paid to the overall benefit of replacing fossil fuel emissions, adding, “The focus of the project is to bring solar power to the community. I think people lose sight of that.”
A Sheep Solution?
Sheep are another option to maintain meadow height. It’s already happening in other solar farms in New York state. One of the largest is the Cascadilla Community Solar Farm, managed by Jessica Renee Waltemyer for Cornell University. “We graze sheep, primarily Finn and Dorset crosses, on about 125 acres of solar panels—10 arrays, each about 12 acres—for vegetation control,” said Waltemyer, who has been working in the animal science department at Cornell since 2010. The sheep live and graze by the solar panels from May through October. In the colder months, they are maintained in barns and fed hay and other feed.
The sheep-grazing project has a contract from the solar company, which pays a fee for the service. The university is engaged in active research to support the solar grazing industry, which is only about six or seven years old, Waltemyer said. Current research suggests that ideal “stocking density” is between six and eight sheep per acre. Those sheep graze one acre for about 10 days, and then are moved to another acre while the original site is allowed to regrow for about 50 days on average. Then the cycle repeats.
“We’ve done multiple studies to help future producers and farmers to find that sweet spot to comply with the contract and have enough to feed the sheep,” Waltemyer said.
The goal is to have the sheep forage so the vegetation is about 4 to 6 inches high, and then move on. “If you graze it too short, the sheep can pick up a parasite called barber pole worm, which can cause them to become anemic and very sick,” Waltemyer said. Plus, she added, the goal is to protect the roots of the vegetation so it can easily regrow. Much like sheep elsewhere, the solar-grazing herds at Cascadilla are shorn for wool, and lambed for meat and also to restock the herds.
“They stay under the panels during the heat of the day, and then, during the cool of the night, they’ll move out between the panels and rotate around the array,” Waltemyer said. “We provide water and mineral supplements and check on them daily. The panels provide shade and wind and rain protection.” A Great Pyrenees dog provides protection against predators such as coyotes.
Waltemyer said the sheep offered an advantage at Cascadilla, where some of the land is swampy and would be difficult to mow mechanically. And because sheep prefer to huddle near the panels, pollinator plants can be grown along the periphery of the array to attracting bees and butterflies without risk of being nibbled. For farmers, the benefit of a solar contract is that they get paid while not needing to pay for either feed or access to land, she said.
While Carson Power has no current plans for sheep grazing, Gordon agreed that “it’s certainly possible at some point in the future to use sheep to graze instead of traditional mechanized landscaping, aka, lawn mowers. But at this point in time it’s not an obvious solution for us here. So we’re not pursuing it. But it’s early days. It’s exciting and interesting.” He noted that the company has worked on other solar projects that include sheep grazing.
To make economic sense, however, there would need to be local sheep herders who are interested in expanding. “If somebody has a herd and they’re already in business, it’s a benefit,” said Waltemyer. Ideally, she said, the solar company would plan for grazing in advance.
“I hear a lot from the public that if we put up solar panels, they’re ugly,” she said. “Maybe there used to be a beautiful hay field. I hear that quite a bit. So I think there’s an opportunity for the solar companies to come in and approach the landowners and say, ‘We want to rent or lease your land for solar panel installation and if you have sheep, how can we make this work for you and us?’” However, Waltemyer conceded, “It takes a lot of communication to make it work.”
Even the presence of sheep herders in and around Pine Plains doesn’t necessarily mean a solar field would work for their purposes. While Fat Apple Farm on Sigler Road keeps a small flock of sheep in addition to cattle and other livestock, the farm sits on 650 acres, providing plenty of grazing land. Fat Apple’s manager John Agostinho said there would be no interest in grazing sheep at a future Pulvers Corners solar farm.
The enthusiasm of the local community was also instrumental in getting the Cornell project underway. “Our town was in support of the sheep grazing—they really wanted to see the land utilized as agriculture,” said Waltemyer. “So there was some push from town. Our arrays are close to walking trails and back roads that people like to walk on, and the neighbors and community members really love to see the sheep.”
In the future, said professor Zhang, solar projects can be designed in ways that make a wide variety of agricultural uses feasible. If rows between panels were wider, for example, crops such as soybean or corn could be grown, or cattle could graze. “You might lose some [solar] power but you would get other opportunities for farming,” he said. “It’s a balance.” His own research has shown that growing crops under solar arrays helps cool down the panels, making them more efficient and longer-lasting.
More advanced solutions, Zhang added, include panels that are controlled to maximize sun exposure for crops, or even vertical arrays to maximize the amount of sunlight reaching plants. He also sees opportunities for solar farms to become integrated into school programs. “When I say we should design solar farms differently, I mean that in a broad sense,” he said. “The solar farm has to be not a fenced-in, industrial facility, but a part of the community.”