This was highlighted at a recent webinar on agrivoltaics hosted by the International Solar Energy Society (ISES) and the Global Solar Council (GSC). Experts from several continents provided insights into trends and new developments. Important drivers for agrivoltaics are land scarcity and increasing drought in many regions as well as technological optimizations and further developments. The prerequisite is to interfere with agricultural use as little as possible and to cooperate closely with farmers for a broader application of Agri-PV. Challenges include international standardization, the removal of regulatory hurdles, effective incentive systems, even more comprehensive monitoring, the even greater involvement of farmers, and further improvements in economic efficiency.
Agrivoltaics has a high potential in India, not only because of the high solar irradiation. After all, India is the world's second most populous country after China. Around 424 people live there per square kilometer, almost twice as many as in Germany. At the same time, it is very agricultural, with 60 percent of its land used for agriculture (39 percent worldwide), although agriculture is increasingly struggling with water shortages as a result of climate change. The government's expansion plans for renewable energy, with a target of 500 gigawatts by 2030, are ambitious. Dominating photovoltaics are ground-mounted systems, which can lead to land-use conflicts in some cases and underscores the need for multiple uses of dwindling land resources via agri-PV.
Experiences and trends in India
Currently, agrivoltaics is still niche, with several dozen pilot plants, but interest is growing rapidly, as reported by Subrahmanyam Pulipaka, CEO of the National Solar Energy Federation of India (NSEFI). Agri-PV systems combined with efficient irrigation methods, whether via drip irrigation, reuse of water used to clean solar panels for irrigation, or rainwater harvesting, are playing a major role. In addition, the shade cast by Agri-PV systems can help reduce water stress on certain crops. Crop cultivation between rows of modules on ground-mounted systems is currently predominant, according to Pulipaka, along with cultivation under rows of modules at conventional heights and under higher elevated modules (> 3 meters).
For example, 40 different crops, including eggplants, tomatoes and potatoes, are grown on the 2.5 hectares between and partly under the module rows of the Agri-PV plant in Amrol (Gujarat). The goal is also to conserve water and minimize the use of agricultural chemicals. The 1 megawatt (MW) plant was implemented by the state-owned utility Gujarat Industries Power Company Limited (GIPCL) in collaboration with Anand Agricultural University and is now being operated and evaluated. Local farmers were also involved in the planning, for example, to install electrical installations so that the planting strips could be easily cultivated with agricultural machinery, Pulipaka reports.
At the Junagadh Agricultural University (Gujarat) Agri-PV pilot plant, which has a capacity of 7 kilowatts (kW), the modules are 3.50 meters (10 feet) elevated, with tomatoes and other crops growing underneath. Trackers with bifacial modules, under which different crops grow, are being tested at the 200 kW facility at Dayalbagh Agriculture University in the state of Uttar Pradesh. New ground is also being broken by a 3kW Agri-PV system on a private rooftop garden in Bangalore, where various vegetables and spices such as beans, spinach, chili and cilantro are grown under the modules and rainwater is used.
However, Pulipaka says there are still a number of hurdles to overcome before agrivoltaics can make a breakthrough in India: For example, the possibilities of the new technology are not yet known in many cases, farmers are not involved in corresponding projects in good time, and there is often a lack of reliable profitability analyses and studies on the influence of the various agri-PV systems on agricultural yields. Technical norms and quality standards are also still lacking, planning law does not provide for Agri-PV, and financial incentive systems for Agri-PV should be created for smallholders, Pulipaka demands. He sees a great opportunity in integrating Agri-PV into the ongoing subsidy program for 3 million solar pumps in India.
Agrivoltaics in the U.S.
Land availability is also becoming an issue in the U.S. as solar targets are dramatically increased to accelerate the energy transition. This is compounded by increasing water issues in many regions, loss of biodiversity, and farmers seeking additional sources of income. About 25 agrivoltaic pilot plants are currently being funded and evaluated under the umbrella of the Department of Energy's Inspire (Innovative Solar Practices Integrated with Rural Economies and Ecosystems) program, Jordan Macknick of the National Renewable Energy Laboratory (NREL) reported.
In addition to crop-based agricultural production, grazing, water management, and biodiversity enhancement, such as supporting pollinators, play an important role in Agri-PV systems, Macknick said. Great emphasis is also placed on developing and providing economic feasibility calculations and standard protocols for vegetation and yield evaluation, as well as working closely with both project developers, nongovernmental organizations (NGOs), and the agricultural community, he said.
One of the lighthouse projects is Jack's Solar Garden in Boulder, Colorado. A farmer converted - also for economic reasons - a hayfield into a 1.2 MW agri-PV system. This is used multifunctionally: In addition to the actual agricultural and PV production area, there are various experimental fields, such as for water management or the promotion of pollinators, and art events, concerts and environmental education weekends are held. In addition to universities and NREL, Jack's Solar Garden also cooperates with the Colorado Agrivoltaic Learning Center, an NGO.
In any case, Macknick sees close cooperation between the various players involved and clear regulations regarding the operation and maintenance (O&M) of the plants, as well as broad availability of data and experience from the pilot plants, as important success factors for Agri-PV projects. He also sees the use of trackers and bifacial or semi-transparent modules as promising, depending on the location and type of plant.
Tailwind also in Germany
The new technology is also making progress in Germany. A boost is expected from innovation tenders and the development of a new standard for Agri-PV (DIN SPEC 91434), which defines agricultural use as a priority over power generation. For example, the loss of agricultural acreage due to PV mounting systems, among other things, must not exceed 10 to 15 percent, and the agricultural yield must be at least 66 percent of reference areas, as Moritz Gajewski of the Fraunhofer Institute for Solar Energy Systems ISE reported. In addition, he said, Fraunhofer ISE is in the process of revising its existing guide to agri-PV and, among other things, identifying opportunities for the optimized use of trackers with the help of artificial intelligence (AI).
Big topic at Intersolar Europe 2022: Innovative agricultural photovoltaic projects and technology - pv Europe
The importance of Agri-PV as an opportunity for agriculture to advance climate protection was emphasized by Petra Högy from the University of Hohenheim. At the same time, reduced evaporation of agricultural crops cultivated under the shade of PV modules is becoming increasingly important in light of increasing heat and drought periods, she said.
Good experiences in the Netherlands
Max Tegtmeyer of BayWa r.e. reported good experience with a 2.67 MW Agri-PV system on a 3.3-hectare raspberry farm in Babberich, the Netherlands. Net crop yield was increased by about 6 percent compared to conventional raspberry cultivation under foil tunnels. Agri-PV systems have also been implemented for the cultivation of currants, blackberries, blueberries and strawberries in the Netherlands, and trials are also underway in pear and apple production in Germany.
It became clear during the webinar how important the international exchange of experience is for the further development of agrivoltaics and the establishment of international standards. The IRENA Coalition for Action Working Group on Renewables in Agriculture also wants to drive this forward, reported its leader Subrahmanyam Pulipaka. (hcn)
