Synergistic benefits of agrivoltaics in enhancing microclimate, solar panel efficiency, and physiological and biochemical attributes of Hibiscus rosa-sinensis.

The growing need for renewable energy coupled with land-use competition for food production, advocates the value of agrivoltaics (AV) as a double remedy to the conundrum of energy and agriculture. This study evaluated the impact of growing China rose (Hibiscus rosa-sinensis) under PV panels on both plant physiology and solar panel performance in arid conditions of Saudi Arabia. A 9 kW PV system located at the University of Tabuk was utilized to examine impact of vegetation on microclimate, PV performance, and effect of PV shading on plant biochemical responses. Sixty-day-old hibiscus plants were grown in pots for thirty days either beneath photovoltaic (PV) panels or in open conditions, and PV operational parameters were monitored using wireless sensors connected to an Arduino-based data acquisition system. Plant physiological and biochemical traits, including chlorophyll, N content, leaf water status, oxidative stress markers, antioxidant enzyme activity, and components of the ascorbate-glutathione cycle, were analyzed in leaf samples. Samples were collected from plants at three locations beneath the PV panels (under PV, front PV, and behind PV) as well as from plants grown in the open without PV panels (control). The results of the study demonstrate that vegetation beneath PV panels significantly reduced surface temperatures above and below the panels compared to bare-ground panels, leading to a remarkable increase in voltage output. This cooling effect was attributed to plant transpiration and improved soil moisture retention, which enhanced panel performance. In addition, shading from PV panels improved physiological attributes, including chlorophyll content, N content, and leaf water content, while reducing leaf temperature. Plants under PV panels also exhibited lower levels of oxidative stress markers such as hydrogen peroxide and superoxide, accompanied by suppressed activity of their biosynthesizing enzymes, whereas antioxidant defense system was markedly enhanced. The ascorbate-glutathione cycle was more efficient under PV shading, maintaining redox homeostasis, while the accumulation of soluble sugars suggests improved stress tolerance. Among the three locations beneath the panels, plants under the PV panels performed better than the those from front and behind the PV panels. In conclusion, the integration of vegetation beneath PV panels not only enhanced panel efficiency through microclimate regulation but also promoted plant health by mitigating oxidative damage and improving physiological resilience. These findings highlight how agrivoltaics can help create renewable energy and climate-resilient agriculture in arid areas, presenting a viable solution to the problems of food, energy, and water security.