New research from France shows that the height of PV panels has a critical impact on airflow and evaporation in agrivoltaic systems, with panel heights of less than 3 meters affecting crops through altered airflow. The scientists emphasized the need for site-specific measurements and computational fluid dynamics to accurately estimate water and energy exchanges among PV panels.
“We have shown that changing the airflow can affect crops when the panels are low, especially when the full throttle height is less than 3 meters,” said the study’s corresponding author Joseph Vernier. pv magazine. “All panels modify airflow, but only low panels will affect the underlying crop through airflow adjustment. Furthermore, if sensors are not placed in locations representative of the power plant, applying literature-based formulas, originally developed for open field conditions, will lead to inaccurate results.”
Vernier also explained that when the height of the full throttle is more than three meters, the panels do not significantly affect the crops below due to the air flow. However, below this threshold, changes in airflow can be as important as the reduction in solar radiation, strongly affecting energy, water and gas exchange – and thus photosynthesis. “Developers need to consider changes in airflow when dealing with low PV panels,” he continued. “Changing airflow certainly has an impact on agricultural yield because it alters evaporation, which is critical to assess whether agricultural voltaic systems can improve agricultural yield.”
Come to the on March 5 Double harvest, double problems: addressing EPC barriers in agrivoltaic system design pv magazine session in English at KEY – The Energy Transition Expo in Rimini.
Experts will share insights on current agricultural voltaic technologies, key design choices and key barriers to standardized, scalable dual-use projects in Europe and Italy, including region-specific EPC issues.
Additionally, Venier said there could also be airflow changes an impact on energy generation. “Depending on the geometry of the agrivoltaic system, the convection around the panels will be different and can lead to variations in the panel temperature,” he said. “Tall panels, with a distance between two consecutive rows of panels of approximately 10 meters, can reduce panel temperatures by more than 3 C to 5 C compared to traditional ground-mounted power stations, increasing energy generation by 1% to 2%.”
Presented in the newspaper “Implications for energy and water exchanges of airflow changes in agricultural voltaic systems”, published in Energy nexusthe research work was based on data collected from three sonic anemometers installed in a 450 m2 agrivoltaic power plant and a 250 m2 control area where crops are grown without PV panels.
The facility consists of four parallel rows of 18 bifacial 560 TOPCon PV modules, supplied by Chinese manufacturer JinkoSolar, with the panels mounted on trackers with tilt angles ranging from -60° to 60°. The rotation axis of the tracker is set to 2.5 m and the distance between two consecutive rotation axes of the tracker is approximately 5.5 m.
Image: Cerea, Energy Nexus, CC BY 4.0
Airflow measurements, averaged from their native resolution to 10-minute intervals, were conducted between November 2024 and March 2025 to ensure sampling under relatively stable surface roughness conditions.
The analysis showed that soil moisture at the agrivoltaic power plant remained above field capacity until spring. In the control zone, moisture declined rapidly in spring without limiting evaporation, but in May the decline slowed despite higher radiation, indicating water stress. In the agrivoltaic section, interrow humidity followed the control trend but was slightly higher, while under PV panels the variations were smaller due to shading.
Rain runoff caused a sharp increase in inter-row moisture, creating bi-scale heterogeneity between the areas between the rows and the areas under the panels. PV panels also affected airflow, generally reducing wind speed, friction speed and turbulence, although the effects varied depending on wind direction and panel tilt. Overall, the impacts on soil moisture and air flow were highly localized within the agricultural voltaic system.
Simulations of wind speed and friction speed for varying PV panel tilt angles closely matched field measurements, capturing the reductions caused by the panels. Vertical profiles showed that wind speed peaked above the panels and decreased within the turbulent wake, while friction speed showed two maxima, highlighting complex airflow patterns. Horizontal profiles showed strong spatial heterogeneity, with airflow between rows reaching up to twice the values under the panels, influenced by the tilt and location of the sensors.
“Evaporation is affected not only by the reduction in solar radiation, but also by airflow changes caused by PV panels, which can lead to variations of 30%,” the researchers said. “Therefore, this study cautions against uncritical reliance on standard methods for estimating evaporation.”
To validate their findings, the team conducted computational fluid dynamics (CFD) simulations, taking into account weather, plant layout, seasonality and spatial variability. This confirmed the qualitative trends when panel height, tilt angle or surface roughness are changed, although quantitative results may differ.
The researchers explained that evaporation should be assessed using direct measurements in addition to CFD simulations to capture the effects of local conditions. In addition, an agrivoltaic specific evaporation formulation is needed, taking into account panel geometry, airflow, radiation and plant height. “However, the main challenge in developing such a formula lies in the dependence of flow variables, radiation and air temperature on the APV geometry, spatial localization and plant height,” they concluded.
This content is copyrighted and may not be reused. If you would like to collaborate with us and reuse some of our content, please contact: editors@pv-magazine.com.
Popular content
