The North American Center for Saffron Research and Development is conducting a multi-year study of saffron crops grown under and adjacent to ground-mounted solar arrays. The study, which began in 2015, includes two years of field data from the Peak Electric solar field in Burlington, Vermont.

Researchers established the saffron corms in three locations within the solar field: in the aisles; directly under the solar panels; and around the perimeter of the arrays. These three locations include both raised beds and in-ground planting methods.

Saffron is a perennial crop suitable for sunny locations in arid and semi-arid regions. It is relatively resistant to cold. Yields typically increase for three years after planting, often increasing exponentially between the second and third years. Saffron is a high-value crop, with values ranging from $19-$55/gram retail. It is also a hand-harvested crop, making it well-suited for agrivoltaics.

In the first year of the field trial, the saffron yield was low, as expected for newly planted saffron corms, with a higher yield in the raised bed plots. The second year of the trial produced higher-than-average yields, with some plots producing yields three times higher –than averages. 

Highest yields occurred in the lots located in the aisle and around the perimeter of the solar panels, with yields of 17 pounds of saffron/acre, which would be equal to $192,775/acre at an average price of $25/gram. 

The plots directly under the solar panels did not show this increase in production. These plots showed a 30% decrease in yield, indicating that the area under the panels is not an ideal micro climate for saffron production. Figure 1 shows the average yield of the harvested saffron per acre during the field trial.

Figure 1. Average yield of harvested saffron per acre during 2019 and 2020. (Ghalehgolabbehbahani et al., 2022)

Research will continue at this facility and the AgriSolar Clearinghouse will plan a field trip for the public in the fall of 2022. The annual report for this study is available in the Information Library here.

Reference

Ghalehgolabbehbahani et al., 2022. Saffron and Solar Farms: A Win/Win for Environment and Agriculture. North American Center for Saffron Research and Development, Burlington VT.

The Monadnock Region Community Supported Solar project in New Hampshire is bringing together farmers, investors, and champions with a goal of helping local farms realize the potential of the renewable energy economy.

Community-supported refers to a synergistic relationship between a business and consumers. Whether it be community-supported agriculture, community-supported fishery, or community-supported solar, this business model allows consumers to have access to a good or service closer to their community, usually one that is healthier and more affordable. This model also allows the local business to have greater security in its operation and be able to spread out fixed costs, usually in the form of “shares” from the consumer.

Here’s how it works. Farmers in the Monadnock region can purchase an electricity share and become a member of the Farmer Member’s Group. Participating farms enter into an operating agreement with Community Supported Solar for Farms LLC. During the LLC phase, farmers contribute by paying for a portion of the solar array installation, and they continue to use their local utilities as usual. Upfront costs are also funded by investors, making the share payments cheaper for the farmers. Community Supported Solar for Farms LLC will work with Cheshire County Conservation District (CCCD), which serves as manager of the LLC, and investors to take ownership of the array in six years through a buyout.

After the buyout occurs, the farmers group will own the system and each share will be net metered, providing free energy to those that have a share. Net metering takes unused power from the array and sends it back to the grid for later use or for others to use. This project utilizes group net-metering, which allows multiple electric meters at different locations to be bound to one solar array. Members of group net-metering benefit from solar energy without needing a solar array on their property. Each share is equivalent to 5,000 kWh of energy. The 90-kilowatt array has been built on host-member Sun Moon Farm in Rindge, New Hampshire, which also grows and sells produce within a community-supported agriculture model.

Photo Courtesy of Sun Moon Farm, Rindge, New Hampshire

The project will realize a host of benefits. Farmers who purchase a share support renewable energy and will benefit from stable, low-cost energy, and the project’s investors benefit from earning tax credits, renewable energy certificates (REC) funds, a state rebate, and extra income on electricity sales to farmers.

CCCD and the Monadnock Sustainability Hub serve as community champions for the project. The CCCD has secured a grant through the New Hampshire Charitable Foundation that will be used, in part, for system buyout in Year 6. CCCD will host a crowdfunding initiative in February 2022 to raise additional funds to lower share costs even more for farmers.

Learn more about the Monadnock Region’s efforts at https://cheshireconservation.org/solar as well as their crowdfunding initiative at https://monadnock.thelocalcrowd.coop/campaign/community-supported-solar-for-farms/.

As with most inventions, necessity drove James McKinion’s design for the Helical Solar dual axis, bifacial solar panel array. In 2016, McKinion wanted to maximize the area above cut pine trees for solar energy. However, it soon became apparent that the cost of bulldozing and clearing tree stumps was cost-prohibitive. He decided to engineer a solution.

Helical Solar installation
Courtesy of Helical Solar

He developed and patented a solar array design and received of several Small Business Innovation Research (SBIR) grants to develop a rural solar solution that could be used with agriculture while lowing electrical cost. The design included a 13-foot solar panel mount height that allowed for cattle grazing, tall crops, and mid-sized tractors. It also ensured landowners would not lose arable land. The panels rotate to follow the sun, so the shade from the panels does not require shade-tolerant crops. All cables run several feet underground, to ensure protection from animals and comply with code, and all cables above ground are encased in array. The access box consists of a heavy steel case designed to withstand an accidental tractor collision.  

McKinion also faced the complexity of anchoring solar panels with a 10- foot screw pile. The cost of an excavator with a boom tall enough to auger the anchor piles far exceeds the energy savings. To address this, he experimented with work-trucks commonly used by municipalities and rural electrical cooperatives, known as Digger Derrick trucks. He then found further cost savings when he decided to ship pre-assembled solar panels and parts to electric utility companies and train them perform the installation with existing equipment and staff.

The design also addressed another rural co-op problem: the lack of reliability among solar installation companies. For example, the Utility Board in Arkansas did not want to recommend solar installers to their constituents because many were not available for troubleshooting and support after installation. Helical’s solution allowed the utility companies to install the system while also providing an interface that would give customers real-time information about the energy being produced.

Helical now has prototypes operating in five states, with plans to update older panels. Currently, they are nine 360-watt bifacial panels in the system equaling 3.24kW. McKinnon estimates that the bifacial panels produce 10% more energy than a rooftop system and that dual-axis tracking produces an additional 35% energy production. The newer panels will be 550-watt series panels for a 4.95kW system. With the total 45% gain from the dual-axis, bifacial set-up, McKinion predicts an output that would typically be seen from a 7.6 kW system. These systems are engineered to offset the energy consumption of a typical single-family home.