This September, legendary broadcaster David Attenborough released the documentary, A life on our planet. In it, he says that preserving biodiversity is one of the key issues we face. At the same time, research published by the University of Oxford found emissions from the world’s food system – said to account for around 30% of total global emissions – could increase temperatures by 1.5°C, even if we “immediately” halted fossil fuel emissions.
These threats may appear detached from the solar industry. However, PV is not only uniquely positioned to address our addiction to fossil fuels. A growing body of evidence shows it could also prove key to solving biodiversity loss and intensive agriculture challenges, including deforestation, soil erosion, land conflicts, pesticides, drought, and desertification.
Taking root
In its broadest sense, agrivoltaics, or agri-PV, involves developing an area of land for the dual purpose of generating solar electricity and growing food. The concept originated in 1981, yet the field didn’t gain much ground until the 2000s.
Since 2014, around 2,800 Agri-PV systems have been deployed worldwide, with a total capacity of about 2.9 GWp, according to BayWa r.e. Regulatory frameworks and support schemes are already in place in Japan, South Korea, China, France and Massachusetts, and reportedly under development in the Netherlands, Switzerland, Austria, Germany, India, and California.
It wasn’t until 2019, however, that this niche market really began to take root. Over the past two years, research, policy discussions, and projects have gained traction, while the first agrivoltaics conference was held this October, attracting over 350 participants from 38 countries.
Increasing yields
As studies indicate, two of the most significant advantages of working towards effective sustainability are partnerships and innovation – and this is something agrivoltaics capitalizes on as agricultural scientists come together with those working on PV applications. In addition to solving intertwined global challenges, there is potential for new business opportunities, products and services, and revenue streams.
This is good news for solar, which can further strengthen its revolutionary potential; and for farming, which struggles to deliver increasing amounts of food to a growing population, and from climate-related events leading to crop failures and/or decreased yields.
A 2019 paper in Scientific Reports titled ‘Solar PV Power Potential is Greatest Over Croplands,’ from Oregon State University detailed a new model created to assess the overlap between solar potential and underlying land use. It concluded the western United States, southern Africa, and the Middle East have the greatest agri-PV potential, based on data sets for solar radiation, air temperature, wind speed, and humidity.
The researchers also found these projects can increase food, water, energy, and climate sustainability. “It is scalable, meaning that we could deploy at large levels and see massive positive impacts,” scientist Chad Higgins from the university’s Department of Biological and Ecological Engineering told pv magazine in June.
He added that agri-PV has a positive impact on all 17 of the UN Sustainable Development Goals. “The technology exists, is profitable in the right circumstances, and has many societal ancillary benefits … It is truly a win-win-win.”
These findings were preceded by a separate report in Nature, ‘Agrivoltaics provide mutual benefits across the food–energy–water nexus in drylands,’ from the University of Arizona. Presenting the results of a multi-year research project investigating how chiltepin pepper, jalapeno, and cherry tomato plants grow in the shade of PV panels in a dryland location, it said two to three times more vegetable and fruit production is possible, compared to conventional agriculture.
In a third 2019 paper also in Nature, ‘Techno–ecological synergies of solar energy for global sustainability,’ the authors identified ten potential beneficial outcomes of agri-PV, including increased foraging resources for managed and native pollinators, increased water-use efficiency, and soil erosion prevention.
Installing PV on the site of crops can further help protect against weather-related damage like hail, frost, drought, and sunburn; and prove more durable than traditional tarpaulins used for protection.
Taking the lead
Against the backdrop of the European Green Deal, which includes the “Farm to Fork” strategy – aimed at producing food sustainably – industry association SolarPower Europe established an Agri-PV Workstream this March. Recognizing the combined potential, the association said they could become the engines of a sustainable European economy.
The project will be chaired by French project developer Amarenco, which aims to push the sector to “the top of the European agricultural political agenda” while also encouraging reforms for the standard agricultural policy.
European agrivoltaics has further taken off this year on a project level. Currently, France is leading the drive, with a number of plans unveiled, including oil and gas company Total’s intention to install nearly 500 MW of agri-PV capacity, and Sun’Agri and RGreen Invest’s initiative to install 300 MW, both by 2025.
Innovation on the AI and module level are also coming out of France, with startup SAS Solar Cloth System developing a PV shade screen, which it claims can become a key element in the development of global greenhouse agriculture. Its flexible panel consists of two films: one copper, indium, gallium, and selenium (CIGS) layer; and another, amorphous silicon germanium (a-SiGe) layer. They are encapsulated in flexible, structured textiles which the manufacturer says offer complete protection of the solar modules.
Deploying vertical mounting technology for bifacial PV panels on the French market is another project underway, with Total having signed an agreement this year with German startup Next2Sun. The mounting structure reportedly allows vertically installed panels to exploit the incident solar radiation on their front and rear sides.
Activity is not just limited to France. In Belgium, researchers at KU Leuven are testing agrivoltaics in a pear orchard. The first pilot project features specially designed 185 W solar panels with transparent backsheets, conventional silicon cells, and 21% efficiency. The research team also created a novel agrivoltaic simulation tool to calculate energy production and tree light interception.
“With this tool, we could model the cell-configuration of the semi-transparent modules,” researcher Brecht Willock told pv magazine in October. “Cell rows in parallel of the tree rows, results in a homogeneous light distribution and offers the best solution for a fixed system.”
He said there is always a tradeoff between the transparency level and PV power, with higher transparency levels resulting in lower PV power density, and vice versa. “However, there is also a financial transparency limit: The needed PV power and energy returns must be calculated in function of the fixed structural costs to be financially attractive … This, in combination with the needed transparency levels for the crop growth, explains the complex design of agriPV set ups.”
In Switzerland, startup Insolight said this August it had raised €4.6 million to bring its concentrating PV module technology to commercial production. Originally conceived for rooftop solar, the product is now being recommended as an interesting option for agrivoltaics. The panels have a claimed efficiency of 30% and a power output of 160 W.
“Insolight intends to sell [the] first modules to large solar energy corporates for application in agrivoltaics. There is a unique potential for high efficiency and translucent modules to produce both solar electricity and crops on the land, whether deployed on fields or greenhouses,” it said.
And against a backdrop of drought, Australian agrivoltaics startup Wynergy said in 2019 it was aiming for an eventual 1 GW of solar capacity in New South Wales. Wynergy offers a mixed land-use proposition and guaranteed income for farmers, who will be paid a lease for hosting PV and receive a small initial shareholding in the projects.
Boosting biodiversity
Focusing specifically on biodiversity is vital for other companies, like Austria’s Eco-Tec. This September, it announced a cooperation with startup Meine Blumenwiese (My wildflower meadow), to ecologically upgrade ground-mounted PV projects. Eco-Tec plants flowers on arable land to create new habitats for insects and wild animals while also aerating the soil; Meine Blumenwiese then maps the resulting biodiversity.
In November, Spain’s largest utility, Endesa, a majority-owned subsidiary of Italian utility Enel, said it is developing beekeeping projects at two PV plants. The initiative is linked to a pilot crop cultivation project between the solar panels of Endesa’s arrays in Carmona.
And it is always possible to increase scale. Living up to its leading solar reputation, China’s Baofeng Group is currently building a 1 GW solar park on a goji berry plantation in Ningxia Province, of which around 640 MW have already been grid-connected. “The ecosystem in this region has improved; the number of small wild animals has increased significantly, like sparrows, hares, and pheasants,” a spokesperson from Huawei, which is providing inverters for the project, told pv magazine in September.
Work to be done
“It has been estimated that deploying Agri-PV on only 1% of global cropland could help meet total global energy demand,” wrote SolarPower Europe when announcing its new workstream. It added, “The potential for Agri-PV in Europe is huge: the technical capacity, if Agri-PV were deployed on only 1% of the EU’s arable land, is over 700 GW.”
Given the potential advantages, it is easy to focus on the positives of agri-PV.
We all want simple solutions to the challenges we face. However, there are many unanswered questions when it comes to its large-scale feasibility. For instance, what needs to be achieved in order to convince farmers of the benefits? How should policy be aligned to support its effective development? What technological changes will be required in equipment to ensure maximum efficiency? And just how financially feasible are such installations?
According to Willem De Vries, project manager for AgriPV at GroenLeven, which alongside BayWa r.e., has designed special monocrystalline solar panels for five pilot projects in the Netherlands, “At this stage, the costs of AgriPV installations are … significantly higher than for ground-mounted installations. But those will drop due to experience, optimizations, and a supply chain that gets used to our special requests.”
SolarPower Europe is also seeking answers to such questions. Through its AgriPV project, it has identified six policy recommendations, including the establishment of specific regulatory frameworks, mobilizing research, and providing financial incentives for farmers and solar developers.
In Q1 2021, pv magazine will be speaking to the main actors in the field of agrivoltaics to gain a better understanding of this nascent market, and to address the many questions it poses. If you want to contribute, contact up@pv-magazine.comfor more details.
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