Impact of agrivoltaics on berry ripening: preliminary results for the white cv. Viosinho

Abstract

Climate change poses significant challenges for viticulture, particularly in Mediterranean regions like Portugal, where extreme heat and drought conditions are becoming more frequent. In parallel, the growing global demand for energy has intensified competition for land between agricultural use and solar energy production. Agrivoltaic systems offer a potential solution by combining crop cultivation with photovoltaic energy generation on the same plot of land. In viticulture, the shade provided by these systems can potentially reduce heat stress, avoid early ripening, and reduce berry sunburn while generating electricity for local consumption or sale to the grid. The objective of this study was to evaluate the effects of an agrivoltaic system as a multifunctional climate change adaptation strategy for viticulture, focusing on the berry ripening period of the Portuguese white grape variety Viosinho at the Lisbon winegrowing region.

An agrivoltaic system was installed in May 2024 over an adult N-S oriented vineyard, trained in a vertical shoot positioning system. Within the agrivoltaic setup two treatments were considered depending on panel position, PVI (panels over the interrow) and PVR (panels over the row) which were compared against a control (C) in full sun conditions. As the panels were installed at pea-sized berries phenological stage, in this work, only the results related to berry ripening are presented. Grape composition analysis was conducted weekly between full veraison and harvest, based on four randomized samples of 200 berries per treatment.

The shading promoted by the panels induced a significantly lower °Brix on the PVI and PVR treatments as compared to the C, at the first sampling date. These differences were maintained until harvest mainly for the PVR treatment. Regarding the relative differences in titratable acidity and pH among treatments, a similar trend was observed but without significant differences. The shaded treatments reached the target maturity (~20° Brix) with a delay of 12 days compared to the C. These preliminary results indicate that the Agrivoltaic system induced a slower ripening, hinting that it might be considered a potential adaptation measure for climate change. Further studies are ongoing to confirm these effects.