RENEWABLE ENERGY Agrivoltaics explained: Power electronics behind solar-sharing farms

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Agrivoltaics refers to the practice of placing photovoltaic (PV) arrays above agricultural land, where solar panels generate electricity for the grid but also provide shade to the crops. During the sunny season, crops shaded by solar panels can grow with a reduced need for extra irrigation, which further lowers water loss in agriculture.

Compared to conventional closely spaced panels in residential and commercial areas, agrivoltaic panels are different because they sit at a height, are far apart, and must support crop microclimate needs. As shading is deliberate and uneven, designs rely heavily on module-level power electronics, such as microinverters. Maximum power point tracking (MPPT) becomes equally important. Real agrivoltaic project deployments worldwide generate power for homes and offices, while supporting the growth of green leafy and root vegetables, including basil, broccoli, corn, maize, wheat, lettuce, potatoes, tomatoes, spinach, strawberries, and many others.

What power electronics does an agrivoltaic project need?

Power electronics of an agrivoltaic system is the same as any other solar panel deployment–DC needs to flow from modules to grid-tie–the point that connects solar panels to the utility grid, or from modules to some storage unit. The newer strategy is placement of modules that support the functioning of far-spaced and elevated panels.

Agrivoltaics can be implemented in several ways, out of which the first method is to use conventional ground-mount systems. The second agrivoltaic implementation method is to use elevated PV systems. Besides crops, animals can graze/take shelter. Both methods are common across real-world agrivoltaic deployments.

In both cases, arrays stay 2-5 m apart, increasing the length requirements for DC links. Conventional solar panels on our rooftops are tightly packed. All of them are connected in series, where equal sunlight falls on each string. In agrivoltaics, wider space between modules varies irradiance, where each string receives an unequal amount of sunlight, complicating further processing.

In series, all panels must share the same current; however, panel current depends on the sunlight it receives. Due to inter-string distance, one side receives more sunlight than the other. The string with higher sunlight adds to the current, while the string receiving lower sunlight caps the whole current.

An optimal solution is to place a DC-DC optimizer, an electronics box, across each panel to stop the weak panel (shaded) from delivering the lowest current. DC-DC optimizers stop the shaded weak panel from dragging down the rest of the current.

The third agrivoltaic implementation method is to use vertical bifacial solar panels on fences or separate support, placed between the fields. Now bifacial panels have two faces: one faces the sun, and the other faces the opposite. The front face processes the sunlight, while the back face processes the reflected light from soil and plants, adding about 5-15% power.

The net power produced in bifacial is more than that of any other agrivoltaic implementation. As a result, engineers need to have power electronic components with a higher rating to process additional output. Extra care is needed during peak hours. The fourth agrivoltaic implementation method is to place solar panels above the greenhouse; however, simulations indicate that crop yields are lower.

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How do inverters and MPPT handle power shading?

MPPT is important for agrivoltaics to maximize energy extraction as conditions vary for crop growth. The real job of MPPT is to match the power generated by PV modules to the actual power requirement needed to be delivered to the load. MPPT algorithm automatically converts and delivers the required power to drive the load.

MPPT algorithms consider sunlight, shading, temperature, angle, and orientation to determine the required power. In residential and commercial solar projects, shading must be designed out; however, shading is a goal for agrivoltaic design. Shading, which changes every day and every season, is critical for crop yield.

Designers cannot apply MPPT to spaced-out panels because one side may show higher power magnitude, while the other responds with lower magnitude. It cannot work on a single setting. They can use several MPPT values and per-panel optimization to recover lost energy. Bifacial configuration adds a second variable, known as bifacial gain, to MPPT, where it does not deliver excess power to result in heat loss. Only “required” power is delivered to the load.

What are design trade-offs?

The main tradeoff in agrivoltaics exists between power and crop yield. Crops under PV modules must deliver similar yields to normal farms, while generating power for the grid. Raising the height of solar panel placement or perhaps increasing the distance between each module affects the power output. On the other hand, the amount of shading can alter crop choices for an agrivoltaic-supported farm. Leafy vegetables and herbs can tolerate 30-50% shade, while others lose yield.

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Market outlook

The agrivoltaic initiative was first introduced in 1981 in Germany by the founder of the Fraunhofer Institute for Solar Energy Systems ISE, Prof. Dr. Goetzberger and Dr. Zastrow. At present, agrivoltaics is supported globally with 600 deployment sites. Other than Germany, many countries have innovated agrivoltaics as aquavoltaics, which is a combination of solar panels and fish farms. In such arrangements, PV arrays are placed over water, in which fishes are farmed.

Simply put, the definition of agrivoltaics has shifted from a combination of power + agriculture + livestock grazing + bee pollinator habitats + irrigation water savings. On the market front, agrivoltaics is valued at USD 14.05 billion and is expected to hit USD 49.44 billion, driven by global climate initiatives. Countries like China, Japan, and Germany are market leaders. According to a recent report, a 3.2 MWp agrivoltaic project in Germany is reported to produce similar crop yields to conventional farms.

References

• https://www.sciencedirect.com/science/article/pii/S2352550925000569

• https://www.nature.com/articles/s44264-026-00141-0

• https://www.mordorintelligence.com/industry-reports/agrivoltaics-market

• https://knowledge.energyinst.org/new-energy-world/article?id=139849

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