Horizontal single-axis trackers key to reduce agricultural yield losses in agrivoltaics

Fraunhofer ISE researchers investigating the impact of single-axis trackers on energy yield and agricultural losses in agrivoltaics have found that their use created an optimal balance between light available for photosynthesis and light available for electricity production.

A team from the Fraunhofer Institut für Solare Energiesysteme ISE (Fraunhofer ISE) has conducted research into tracking strategies that balance light distribution between crops and solar panels in agrivoltaic installations.

The research paper, “Enhancing agrivoltaic synergies through optimized tracking strategies,” available in the Journal of Photonics for Energy, acknowledges that horizontal single-axis tracker (HSAT) systems can help mitigate agricultural yield losses in agrivoltaics.

The study proposes a methodology for optimizing solar panel positioning by using specific irradiation targets to meet different light requirements of crops.

Using a case study of apple orchards in Nussbach, southwestern Germany, the researchers ran simulations via APyV, a custom tool that utilizes advanced ray tracing techniques to assess how solar panel positions would impact light availability for crops. The tool is capable of automating design optimization of agrivoltaics based on key performance indicators, interface with different crop models and the integrated simulation of specialty crops.

The case study found that tailored solar panel control led to 91% of the light needed for the apple trees being delivered over the course of the year, leading to a 20% reduction in solar energy production.

“Our study shows that the combination of solar energy and farming can be enhanced by smart PV-trackers that adjust the position of solar panels based on weather conditions, crop types, and their growth stages,” said corresponding author Maddelena Bruno. “This approach ensures an optimal balance between light available for photosynthesis and light available for electricity production.”

The study also acknowledges that there were periods when the light requirements of the apple trees were not fully met, which it says “highlights the limitations of crop-based optimization.”

In the research paper’s conclusion, the researchers write that despite identified limitations, the study “lays a strong foundation for future research that is already underway.” “Effective control of panel positioning can help preserve agricultural yields while adhering to the yield loss thresholds required to access subsidies, ultimately improving the viability of agrivoltaic systems,” they added.

The researchers also wrote that a proposed absolute targets and control strategy will be field tested in Nussbach during the 2024/2025 season, “contributing to a deeper understanding of the impact of agrivoltaic systems on apple orchards and the surrounding environment.”