Agriculture: the Agrivoltaic Approach – With Video

“Agri” means related to food production. “Voltaic” is all about electricity production. Water, energy, and agriculture, when addressed together, can improve food production, reduce water use, create energy, and add revenue to farmers’ incomes.

An agrivoltaic approach to agriculture is definitely different than traditional farming — solar panels are positioned to allow plants just the right amount of sunlight, and then the excess sunlight is harvested for electricity. The approach creates more sunlight than it would without crops below the arrays, as plants help keep the solar panels cool, which makes them more productive.

Solar PV technology represents one of the fastest growing and most promising methods — environmentally and economically — to reach a sustainable energy system. The global installed capacity of agrivoltaics, or the co-development of the same area of land for both solar power and agriculture, has grown rapidly from about 5 megawatts (MW) in 2012 to approximately 2,900 MW in 2020.

Why Agrivoltaic Systems in Agriculture are Needed Now

The continuous supply of food, energy, and water resources under the additional pressures caused by climate change is a global grand challenge. Population growth and escalating demands for clean energy, food, and water also impose mounting pressure on agricultural land, necessitating the rapid development of innovative, holistic, and climate-compatible solutions.

Scientists are now planting experimental gardens and pushing the potential of an agrivoltaic approach to agriculture. A recent Oregon State University (OSU) study estimates that converting just 1% of American farmland to agrivoltaics could meet the US national renewable energy targets, save water, and create a sustainable long-term food system. Here are the OSU findings:

• 20% of US total electricity generation can be met with agrivoltaic systems if less than 1% of the annual US budget is invested into rural infrastructure.
• Agrivoltaic systems align well with existing Green New Deal goals.
• Widescale installation of agrivoltaic systems can lead to a carbon dioxide (CO2) emissions reduction equivalent to removing 71,000 cars from the road annually and the creation of over 100,000 jobs in rural communities.
• Agrivoltaics provide a rare chance for true synergy: more food, more energy, lower water demand, lower carbon emissions, and more prosperous rural communities.

Agrivoltaic systems, which deliberately maximize the utility of a single parcel of land for both solar PV electricity production and agriculture, have been demonstrated as a viable technology that can ameliorate competing land uses and meet growing energy and food demands efficiently. The diversity of possible agrivoltaic applications presents ample opportunity for creative agricultural co-location that reflects local community interests, mitigates land use conflict, and increases the economic value of farms deploying such systems.

Life Cycle Assessment methodology has demonstrated that agrivoltaic systems have similar environmental performance in areas such as resource consumption, eutrophication, and climate change compared to traditional operations but generate valuable auxiliary benefits, which suggests co-located systems are environmentally superior. Indeed, agrivoltaic systems are superior to traditional ground-mounted PV arrays in terms of their ability to leverage a single plot of land for dual purposes and, consequently, reduce the environmental impacts associated with each enterprise, which may be key in positively influencing social acceptance of solar development on agricultural land.

Examples of an Agrivoltaic Approach to Farming

Agrivoltaics consists of integrating PV modules above the crops in order to enhance climate resilience and allow sustainable food and energy production on one single piece of land.

Indigenous peoples have planted under the shade of the mesquite and paloverde trees of Sonoran Desert for thousands of years. As they did so, they protected their crops from intense sun and reduced the amount of water needed. A recent Washington Post article described how today, in the Santa Catalina Mountains north of Tucson, canopies of elevated solar panels helps to protect rows of squash, tomatoes, and onions. Even on a November afternoon, with the temperature climbing into the 80s, the air under the panels stays comfortably cool. Vegetables such as squash, tomatoes, and onions are being tracked in an agrivoltaic project at Biosphere 2 out of the University of Arizona.

Jack’s Solar Garden in Boulder County, Colorado, is the largest commercially active agrivoltaic system researching a variety of crop and vegetation growth under solar panels not just in Colorado but in the US. Over 3,200 solar panels create a 1.2 MW community solar garden — enough to power over 300 homes. It is a model for farmers along the Front Range on how to produce renewable energy while improving agricultural production via agrivoltaics. Additionally, 40 types of plants, such as blackberries, herbs, and tomatoes, are in the process of being sowed under the solar arrays, and 3,000 trees, shrubs, and other pollinator-friendly plants have been planted around the solar arrays.

Sun’Agri has installed a viticulture agrivoltaic system in the Vaucluse department of southeastern France in partnership with the local chamber of agriculture as part of the Sun’Agri 3 program supported by the French Environment and Energy Management Agency. The goal was to see how agrivoltaics perform in specific crop cultures. “Out of 1,000m² of vines planted with [the] black grenache [red wine grape], 600m² were covered by our dynamic agrivoltaic system,” the Sun’Agri spokesperson said. The 280 panels used have a generation capacity of 84 kW, were placed at a height of 4.2m and can be moved in real time using an artificial intelligence (AI) algorithm the French agrivoltaic specialist has been developing for more than a decade.

Benefits to Solar Developers & Agricultural Land Managers

Rated Power offers a series of benefits of co-locating solar and crops.

Benefits to solar developers include:

• Reduced installation costs: The use of previously tilled agriculture may prevent the need for expensive grading to flatten land to a usable level.
• Increased PV performance: Vegetation under modules can contribute to lower soil temperatures and increase solar performance.
• Accelerate the energy transition — by joining forces with the land managers and rural areas, more owners would probably be interested in using their lands for energy purposes too.
• Building closer links with the agricultural world: Large-scale photovoltaic farms have created a lively controversy in the agricultural world and by adapting to the sector and favoring both activities, the solar industry would see a greater ratio of their project acceptance.
• Reduced upfront risk: Geotechnical risks can increase the cost of solar installation due to increased testing needs. Previously tilled agricultural land was identified as the “least risk option” during a series of surveys with solar installers.
• Reduced legal risk: By using previously disturbed land, solar installers can reduce the risk of up front litigation during the environmental review process.
• Marketing opportunity to a sustainability-minded audience.

Benefits to agricultural land managers include:

• Reduced electricity costs: Developers and landowners may reach an agreement to allocate a percentage of the generated electricity to the land and/or town.
• Diversification of the revenue stream.
• Increased ability to install high-value, shade-resistant crops for new markets: The shading by the PV panels provides multiple additive and synergistic benefits, including reduced plant drought stress and more constant temperature as the panel will maintain the temperature higher at night and colder during the day.
• Potential to extend growing seasons.
• Ability to maintain crop production during solar generation.
• Allow for nutrient and land recharge of degraded lands.
• Potential for water use reduction.

Final Thoughts

“We’ve had 5,000 years of farmers trying out different strategies for dealing with heat, drought and water scarcity,” said Gary Nabhan, an ethnobotanist and agrarian activist who has had a nearly lifelong commitment to healing wounded landscapes from a primary objective of consciously conserving healthy relationships on all levels and planes. Collectively, he added, “we need to begin to translate that.”

Nabhan says the key concept is that “we’re trying to fit the crops to the environment rather than remaking the environment.”