Sheep Grazing to Maintain Solar Energy Sites in Pennsylvania

Background

Solar energy is experiencing significant growth in Pennsylvania, with new ground-mounted solar arrays being installed in several regions of the state. Some estimates place long-term utility-scale solar energy development at 80,000 acres in Pennsylvania by 2030. Solar installations require a large-scale effort to maintain the site. Vegetation needs to be maintained to function as ground cover, but at the same time, remain under control. Maintaining deployed solar energy sites is a significant expense for solar energy companies.

Sheep and lamb inventories in the United States, and specifically in Pennsylvania, have steadily declined over the past 75 years. According to USDA historical figures, the national inventory of sheep and lambs peaked at 49,000,000 head in 1942, then dropped to 17,726,000 by 1973 and to 9,000,000 by 1989. Today, there are 5,200,000 sheep and lambs in the United States. In Pennsylvania, the inventory was 160,000 head in 1971 and dropped to 98,000 head by January 2022. At the same time, there has been considerable growth in ethnic populations in the northeastern United States, many of whom consider sheep and lamb meat among their preferred meats. Much of this market is supplied by sheep and lambs trucked from long distances or imported. Efforts to encourage sheep production in Pennsylvania and surrounding states have been ongoing.

Sheep grazing has proven to be a successful way to maintain solar energy sites in many states. Furthermore, grazing sheep is often more cost-effective than a more traditional approach using people, machinery, and herbicides at similar locations.

Concerns have been raised about the loss of productive farmland for solar development. Densely designed solar arrays are not conducive to the operation of modern farm equipment. Sheep grazing has been identified as one way to make productive agricultural use of land that is also being used for solar energy generation.

Size of Solar Installations

Solar energy can be generated from a variety of deployed systems, including units that attach to houses and building roofs. Ground-mounted systems can encompass anywhere from a few acres to hundreds of acres. Generally, community-scale solar projects range from 10 to 50 acres. Utility-scale systems are typically larger and can run to hundreds of acres. Some ground-mounted solar systems are engineered to track the sun's movement.

Using Sheep to Maintain Solar Farms

Sheep are successfully being used to control vegetation between ground-mounted solar arrays. Sheep can physically fit under the solar panels and can graze all parts of the land area. Sheep are complete grazers and will graze not only grasses and legumes but also forbs, including various weeds. Anecdotal reports indicate that grazing sheep do a more complete job of removing vegetation compared to people with weed-whackers. Experience has shown that any breed of sheep can potentially be used. Hair sheep breeds are popular choices among sheep owners who have ventured into solar farm grazing.

Livestock owners frequently ask questions regarding using other ruminant livestock species to graze between solar arrays. Cattle are too large for typical solar systems and can subsequently damage equipment. Furthermore, cattle cannot physically graze under the lower parts of the panels. This leaves a significant area of land unable to be maintained through grazing cattle. A solar array designated for cattle grazing before installation can be designed with solar panels on pedestals that allow cattle to graze under the entire system.

Goats can graze under all parts of a solar array. However, due to their curious nature and tendency to climb, goats are not recommended for maintaining solar arrays. There have been reports of goats damaging panels with their hooves while climbing on them. Also, there have been reports of goats causing damage from chewing.

Production Systems

Questions that emerge in discussions about grazing sheep under solar panels include which animal class will work best, how lambing fits into the system, and which forage species work best for solar farm grazing. This type of enterprise presents obvious constraints on what can and can't be done.

Agronomic aspects, such as soil fertility, compaction, erosion gullies, and forage establishment, are ideally addressed well before installing solar arrays, while machinery operations are still possible. Even if you are a landowner not in the sheep business, addressing agronomic concerns before installation will make your farm more attractive to a livestock owner interested in maintaining the solar farm with sheep.

Establishment of forage species for grazing can be accomplished much more effectively before solar arrays are installed. Once the solar panels are there, establishing pasture under the panels will be impractical, and establishing new pasture between panel rows could only be accomplished with very small equipment. Study soil characteristics to make sure you select the right plant species for the conditions. Currently, some seed companies are marketing pasture species mixtures for solar farm grazing.

Most solar arrays are surrounded by secure fencing. Sheep owners do not need to install perimeter fencing on the property. However, occasional problems can occur where a gap exists between the bottom of the fence and the soil in undulating terrain or eroded areas. Sheep owners need to set up their own temporary interior fencing to manage rotational grazing inside the perimeter fence.

The secure fencing around the perimeter of solar arrays makes the grazing area basically secure from terrestrial predators. Although bald eagles and black vultures have caused predation issues with sheep, most of the problems have been with very young lambs. Some solar sheep grazers use guard dogs, but most do not.

Sheep owners need to provide water in most situations. For most producers, this has been manageable since sheep are efficient water consumers. At various points in the grazing season, sheep do not consume water in addition to what is already available in the forage. Water can be easily hauled in plastic totes or drums to where it is needed on the property.

Sheep owners grazing solar arrays have found that the panels provide necessary shade for the sheep, and the infrastructure also serves as a windbreak during the colder parts of the grazing season. Interestingly, anecdotal observations among solar-grazing sheep owners indicate that the panels do not impede productive forage growth through shading.

Most sheep owners who graze sheep within solar arrays do not lamb at the site or take ewes with lambs to the site. Some have found that an early lambing system, where lambs are weaned before the grazing season begins, works well. After weaning lambs, dry ewes are transported to solar farms to spend the grazing season doing maintenance at the site.

Other sheep owners have found that they can successfully and profitably maintain a flock of dry ewes for grazing. Another possibility may be using a flock of wethers or yearling ewes to graze each season. Each producer interested in grazing solar farms will need to carefully consider their own resources to determine what works best for their situation.

For mature ewes, experience in New York and Michigan indicates that a typical stocking rate is 3 ewes/acre. As with any discussion of stocking rate, the land's carrying capacity needs to be considered, as it can be affected both positively and negatively by variations in soil quality and fertility.

Business Aspects

As a sheep owner, you need to be compensated for grazing under these large commercial solar arrays. Do not approach this as a 'free grazing' opportunity. Any custom grazing enterprise should be carefully considered before entering into a contract. The sheep owner should consider the costs incurred throughout the whole process. These include livestock maintenance in the off-season, transportation, portable handling equipment, labor, etc. Surveys of sheep owners who graze solar arrays conducted by Cornell University reported that direct contract grazing fees in the eastern United States averaged $326/acre and in New York, $555/acre. These figures are for grazing during the whole season, typically from April through October. In some cases, grazing services are contracted through a landscape company at a somewhat lower per-acre fee than direct contracting.

Sample contracts are available from the American Solar Grazing Association.

Sheep owners considering grazing solar farms need to discuss this enterprise with their insurance agent. Your insurance agent can recommend how to extend your coverage to the grazing site. This has not been an obstacle to the success of solar grazing arrangements.

As mentioned earlier, experience in other states shows that using sheep to maintain solar farms can lower maintenance costs for solar energy companies compared to traditional maintenance approaches. Furthermore, sheep grazing eliminates the risk of tractors or mowers bumping into solar equipment or of mowers throwing stones that can damage solar panels. These facts place sheep owners in a strong position to secure a favorable grazing contract.

Communication

Working under contract to graze solar arrays involves more communication than what many livestock owners are accustomed to. The sheep grazer will need to communicate with the site's operations manager. The sheep owner will also need to communicate with company employees who will be onsite performing routine maintenance on a weekly to monthly basis. For example, closing and securing gates is a common concern. Some sheep owners opt to provide training for company employees so they know what to expect when the livestock are grazing. Keep in mind that most of the company's employees probably have no experience with livestock whatsoever. Some sheep owners have found it beneficial to post signage with their contact information for company employees in case they have questions or concerns.

Some sheep owners are required to use personal protective equipment, such as a hard hat and safety vest, when on site. This requirement may be negotiable in the grazing contract.

Sheep owners who provide grazing services should be aware that they may be more likely to receive questions from the general public, especially if the animals are easily viewed. This communication will involve educating people about sheep husbandry and welfare. Explaining production practices in a non-defensive manner is important to develop a positive image.

Pros, Cons, Opportunities, Challenges

Providing sheep-grazing services to manage vegetation presents opportunities and challenges. Producers are cautioned not to think of this as 'free grazing'. Careful consideration is needed on several production and business aspects. If you don't currently manage grazing on your home farm, then entering into a contract grazing arrangement is not advised. Furthermore, if you do not generally care to communicate with people, this type of enterprise may not be advised.

There are many potential benefits to this enterprise. Obviously, it has the potential to raise your farm income and can be viewed as a growth area for your farm. It can be a way to diversify and provide an income stream not tied to the sheep/lamb commodity market.

From a production standpoint, a custom grazing arrangement effectively increases your acreage and may allow you to devote more land at home to producing stored forage for winter. Also, moving sheep to a solar array for all or part of the grazing season can help alleviate difficult parasite problems in home pastures.

Providing grazing services can bring its share of challenges as well. One challenge may be insufficient wintering space for the number of sheep required to maintain a solar farm. Another problem is the under-grazing of fenced acreage at the home farm.

Sheep owners in the solar-array-grazing business report driving time and distance as challenges. Furthermore, investing in a trailer, handling equipment, watering equipment, and mineral feeders can be challenging.

Summary

Sheep are very well-suited to maintain solar arrays and have proven to be a cost-effective option for solar power companies. Sheep owners interested in contracting to graze sheep on a solar array need to consider many production and business questions. Communication is an important aspect of this type of grazing enterprise.

Sheep owners interested in providing grazing services to maintain a solar array need to fully understand the opportunities and challenges within the constraints of their time and resources.

Sheep numbers have declined for over 75 years in the United States. That decline has also affected Pennsylvania. However, Pennsylvania is situated near a large population center with significant ethnic populations who are frequent consumers of sheep/lamb meat. Although the current inventory of sheep and lambs in Pennsylvania cannot meet the maintenance needs of projected solar industry growth in the state, it is conceivable that the solar energy sheep-grazing enterprise could be an avenue for growth in the sheep and lamb business to help supply regional markets in the future.

Thanks to the following for contributions to this article: American Solar Grazing Association; Cornell University David R. Atkinson Center for a Sustainable Future; Dr. Richard Ehrhart, Michigan State University; Dr. Niko Kochendoerfer, Cornell University; Tom Murphy, Penn State Marcellus Center for Outreach and Education; Melanie Barkley, Penn State Extension Livestock Team; Caroline Owens, Owens Farm, Sunbury, PA.