In its 150-year history, Paul Knowlton’s farm in Grafton, Mass., Has produced vegetables, dairy products and, most recently, hay. The evolution of the farm’s use turned on changing markets and a variable climate. Recently, however, Mr. Knowlton added a new type of cash crop: solar power.
For Mr. Knowlton, a fifth-generation farmer and current owner, said it was an easy call. He had already installed solar panels to provide electricity for his home and barn. When a real estate agent came knocking to see if he was interested in leasing a small part of his land for a solar array, “she planted the seed that I could do more,” Mr. Knowlton said.
Mr. Knowlton looked at several companies but was most impressed with BlueWave Solar, a developer in Boston that focuses on solar installations and battery storage, which allows excess electricity to be fed to the power grid. Soon, two small parcels of largely unused land were made to house low-to-the-ground panels that produce power. This year, Mr. Knowlton’s farm will go one step further: In a third parcel, solar panels will share space with crops so that both can thrive.
This approach is called agrivoltaics – a portmanteau of agriculture and voltaic cells, which transforms solar power to electrical power. Also called dual-use solar, the technology involves adjusting the height of the solar panels to as much as 14 feet, as well as adjusting the spacing between them, to accommodate equipment, workers, crops and grazing animals. The spacing and the angles of the panels allow light to reach the plants below, and the added benefit of shielding those crops from extreme heat.
The electricity is generated to the grid, typically through nearby substations. While some of the electricity may find its way to the host farm, the projects are devised to provide power for general use. And such an solar installation provides an alternative source of revenue in the form of payments to landowners like Mr. Knowlton or a reduction in lease payments for tenant farmers.
BlueWave has focused heavily on designing the projects, then selling them to companies that build and oversee them. The Grafton project, on Mr. Knowlton’s farm, for example, is now owned by the energy company AES Corporation.
“Not only do agrivoltaics advance clean energy imperative but they are critical to maintaining working farms,” said John DeVillars, one of BlueWave’s three co-founders and chair of the board’s directors.
Dual-use solar became interest more than a decade ago because “big installations in the middle of nowhere are going to solve all our energy problems – transporting that energy can be very expensive,” said Greg Barron-Gafford, a biogeographer. and an assistant professor at the University of Arizona. Farms in many parts of the country are in peri-urban areas, transition of zones from rural to urban land. Their proximity to high-use metropolitan areas makes open farmland particularly suitable for solar arrays, but in the past, without any coexisting agriculture, the kind of placement that can set up a conflict over whether food or energy production should prevail.
In a study by AgriSolar Clearhouse, a new collaboration to connect farmers and other landowners with agrivoltaic technology, the installations were also shown to increase foster growth by shielding crops from rising temperatures and with increasing water conservation. While the technology is currently in its infancy in the United States compared to countries in Europe, where the technology has been used for over a decade, federal regulators as well as academics and developers are working to remedy that disparity.
The early results are promising, said Garrett Nilsen, acting director of the Solar Energies Technologies Office of the US Department of Energy. “There is a project in Arizona where they’ve seen a threefold increase in crop yields when they are underneath this kind of system and up to a 50 percent reduction in irrigation requirements” because the panels provide, he said. Additionally, the plants under the panels release water into the air, which cools the modules, creating what Mr. Nelson described it as a “symbiotic relationship between the plants and the panels.”
BlueWave’s first project to go live is a 10-acre farm in Rockport, Maine – now owned and operated by Navisun, a solar power producer. Wild blueberry cultivars have been planted below solar panels, which will produce 4.2 megawatts of power; The project is estimated to produce 5.468 kilowatt-hours annually – plus the amount of power needed for roughly 500 US households.
Unlike Massachusetts, Maine does not offer significant incentives for the use of solar power, so there was a 10 to 15 percent premium on costs when compared with similar projects, which BlueWave absorbed, Mr. DeVillars said. (That practice is consistent with the company’s status as a so-called B-Corporation, which requires a commitment to social and environmental goals.)
Other players are clearly seeing the potential of agrivoltaics: In May 12, Axium Infrastructure, an investment management firm, announced its acquisition of BlueWave. Trevor Hardy will continue as chief executive and Eric Graber-Lopez will continue as president. DeVillars will become chairman emeritus.
Mr. Hardy said the sale would allow BlueWave to expand so that it would operate and not just develop, solar installations and battery storage. Ultimately, he said, the sale “puts us in a bigger place for dual use.”
“Farmers work on a long-term basis,” he continued. “It’s more compelling to drive up farm roads and sit with the owners at their kitchen tables and say that we develop, own and operate the installation.” And the technology’s potential goes well beyond blueberries; Agricultural uses include vineyards and shrimp farming.
BlueWave is not the only agrivoltaics developer. According to the Fraunhofer Institute for Solar Energy Systems ISE, based in Germany, five megawatts of power were produced through these systems in 2012; By 2021, 14 gigawatts of power were generated in dual-use systems – roughly opposite to electricity needed for nearly two million US households annually, according to a spokeswoman from the Department of Energy’s technologies office. And the technology is evolving rapidly; In the few years since the installation at Mr. Knowlton’s farm has adjustable panels that can move to maximize the capture of sunlight, for example.
“It does not always pay to be a pioneer and it is very challenging at times,” said Mr. Hardy, who grew up in a South African farming family. Finding suitable sites – where there is enough sun and proximity to a substation or other electrical infrastructure – can be difficult. Opposition from neighbors, especially where panels are visible from other homes or even the road, is not uncommon.
Indeed, BlueWave was one of several defenders named in a suit planned for agrivoltaics in Northfield, Mass. A state court recently ruled that the neighbor was standing to challenge the proposed development. One of the plaintiffs, Christopher Kalinowski, said there were concerns that his views would be obstructed and that “the area would lose farmland.” (Mr. Hardy declined to comment on the litigation.)
In addition, some chapters of the Audubon nonprofit environmental organization have been vocal about the technology’s potential impact on wildlife. Michelle Manion, vice president of policy and advocacy for Mass Audubon, said that while Her organization supported renewable energy, including solar farming operations, “We want to maximize the placement of ground-mounted solar on some of our lands that are at least ecologically sensitive first.”
And there are general concerns that even with dual-use solar panels, arable land may be lost, though BlueWave says that the land can be reverted to use pure agriculture once the solar leases – typically 20 to 30 years – expire.
But one of the most significant obstacles is cost. The skyrocketing cost of steel has a direct effect on agrivoltaics’ emphasis on raising the panels 10 to 14 feet. “For every foot you go up you need to go two feet into the foundation,” Mr. Hardy explained. “It’s a challenging industry when you think of what we need to do to reach climate goals. But we’re staying the course. “
Ultimately, though, everything depends on how the crops taste: If the flavor or even the appearance of the strays too far from that of the traditional produce, the technology will be a hard sell. But in an early study, researchers at the Biosphere 2 Agrivoltaics Learning Lab at the University of Arizona found that tasters preferred the potatoes, basil and squash grown with agrivoltaics. Beans, however, may take some time: the small sample of tasters preferred the traditionally grown version.