Can agrivoltaics fuel the growth of sustainable farming?

 Agrivoltaics, an emerging segment in solar energy, could be part of the solution by changing the way we harvest crops. As one of the earliest industries to adopt solar, many farms today already have solar energy systems installed on the rooftops of barns, sheds, and other structures. The solar power generated can be used for driving irrigation pumps and other critical systems on the farm, or for selling to the local utility as a steady source of income. But with agrivoltaics, solar energy can be produced on a much larger scale, while overcoming the land conflict between solar and agriculture. Agricultural land occupies about 43% of the surface area of the 48 contiguous U.S. states. This sometimes creates land-use conflicts between farmers and utility-scale solar farms. But new agrivoltaic solutions, where a solar installation is combined with agricultural activities on the same piece of land, are increasingly seen as a productive and profitable option – some may say, a new type of cash crop.

The recent Inflation Reduction Act passed by Congress, lauded as the largest climate change investment in U.S. history, features a $369 billion investment in clean energy. This includes, over $20 billion to support climate-smart agricultural practices that will likely include more grants or subsidies for agrivoltaic projects.

Agriculture + Solar: A Win for Both Teams

With agrivoltaics, the solar panels are elevated high above the ground on a racking system while crops are cultivated underneath, or between rows of crops.  This dual-usage creates massive potential for farmers and solar energy system owners. With dual-use farming, solar panels produce electricity, reducing energy costs for farmers while also providing the crops underneath with numerous benefits, such as protection against hail, wind damage, and overexposure to the sun.

One major study by the Fraunhofer Institute for Solar Energy in Germany looked at a raspberry farm in the Netherlands, whereby 7.5 acres of the almost ten-acre farm was converted into a 2MW agrivoltaic system with raspberries being grown underneath the panels. After testing different types of solar panels, they could produce raspberries of the same quality or better. Another benefit was that the fruit grown under the solar panels did not sustain any damage from summer storms or hail, unlike the fruit that was grown in the open field or under traditional plastic crop covers[i].  Several similar studies from around the globe show that agrivoltaics can improve the yields of shade-tolerant crops or high-value crops, including berries, soft fruits, asparagus, hops, and more, all while providing shade for workers and producing clean energy.

With another recent study on a Kenyan farm, crops such as cabbage, lettuce, and eggplant grew up to a third larger than those farmed in the open, while the farm’s energy costs were halved. In addition, elevated solar panels reduced the water loss from plants and soil while the shade provided was able to shield the crops from UV damage.

 Agrivoltaics Offer Many Opportunities with New Challenges

One of the major challenges to a successful agrivoltaics project lies in planning and optimal utilization of the solar energy and agricultural production.  Installing any type of agrivoltaics must both maximize the energy revenues generated from solar without having a negative impact on the crops. That is why the technology selected for these types of installations is critical. Any type of change in the humidity rainwater runoff, or amount of light coming through the solar panels can have a drastic effect on the success (or failure) of the crops, while the upfront investment costs of these types of solar installations can present an obstacle for investors. The costs must be calculated and planned carefully to best optimize the farm for both crops and solar energy systems – so that both that farmers and the solar investors benefit. This is a major factor in making agrivoltaics sustainable for widespread adoption.Elevated solar panels can reduce the impact of hail, wind, and heavy rain while producing shade to protect crops from overexposure to the sun and keeping the soil moist. In this case, it is critical to use the correct type of solar panel so as not to overexpose or underexpose the crops growing underneath. However, changing the structures of the panel, or using panels which allow more light to shine through, may diminish energy production – which can create a conflict for system owners.

Luckily, solar technology today is far superior to what it was even five or ten years ago.  New technologies in solar, such as Module-Level Power Electronics (MLPE), allow us to maximize both the crop harvest and the solar energy yield. This is because MLPE technology, such as Power Optimizers, improves the energy production of the system by enabling each panel to produce at its individual maximum energy level, regardless of panel orientation or shade /dirt exposure. This enables more effective utilization of farm space.

A SolarEdge system with Power Optimizers paired with solar trackers, can further help maximize both the harvest and energy yield. SolarEdge Power Optimizers ensure that each panel delivers the maximum amount of solar energy possible. At the same time, the trackers use Artificial Intelligence (AI) to understand solar and agricultural seasonal patterns to tilt the panel as the sun moves in various directions throughout the day to boost power production. Together, these key technologies allow for the optimization of both solar energy and crop growth – reducing the system payback time and maximizing the Return on Investment (ROI) for the solar energy system owner while facilitating conditions for crop growth.

In other cases, vertically mounted bifacial panels – panels that can produce solar power from both sides – can be used to allow for more arable land. Here too, using MLPE, such as Power Optimizers, more power can be harvested from the installation. They can also help mitigate power losses caused by module mismatch, which is not uncommon in bifacial panels, due to reduced surface albedo and irradiance differences on the rear side together with increased levels of dirt or shade due to the ground proximity.

Livestock for Solar Grazing: A Path to Coexistence

Agri-PV also offers another major benefit to farmers: new land for grazing herds. Ground-mounted PV systems often require land-maintenance contracts to keep the weeds and grass from overgrowing and reducing the panel efficiency. When vegetation grows too thick underneath the panels, livestock can be used to graze. This model, when appropriately managed, provides another win-win for both parties involved. The herds benefit from access to feed, extra shade from the panels, and additional safety from predators due to secure fencing. In turn, the system owners benefit from grazed pastures, reduced O&M costs from mowing, additional monitoring from on-site farmers, and strengthened relationships with local communities.

The Buzz About Bees, Butterflies, and Solar

The most significant threat to pollinators, especially bees and butterflies, is climate change and habitat loss due to human conversion of grasslands for other land use. But some studies show that solar farms can have many benefits for bee and butterfly farmers when designed with pollinator-supporting plants, such as prairie-clover or other wildflowers.   About 25% of native bee populations in the US are at risk of extinction, while monarch butterfly populations have declined about 68% over the past two decades[1]. This is leading some ground-mount PV installation owners to introduce pollinator-supporting plants that are critical to our ecosystem, planning in conjunction with local beekeepers and conservation specialists to develop habitats that research and support bee or butterfly species over long periods of time.

The Most Efficient Solution Comes from Selecting the Right Technology

Selecting the right solar energy solution is crucial to the success of any agrivoltaic project. SolarEdge’s smart C&I solutions are ideal for agriculture as the Power Optimizers maximize renewable energy generation while the solar trackers can adjust to the sunlight improve crop yields. Having a smart solar energy system that can provide a combination of added benefits like panel-level monitoring, remote troubleshooting, and enhanced safety features is key to maximizing power generation, increasing the lifetime revenue of the system, and improving ROI.

When agrivoltaic projects are planned in cooperation with local farmers, the solar and agriculture industries can work together to make considerable progress towards both transforming food supplies and accelerating the transition to clean energy. At first glance, the symbiosis between the two industries may seem challenging, but new smart solar innovations can tackle today’s challenges and ultimately create a brighter future for our planet.