Modelling Canopy Temperature of Crops With Heterogeneous Canopies Grown Under Solar Panels

Abstract

With global warming and the increase of heatwaves frequencies, it has become urgent to protect crops. Agrivoltaic systems tackle this issue by shading plants with photovoltaic panels to lower the temperature of canopies. However, a permanent shading would lead to an important loss of carbon for plants. For this reason, dynamic agrivoltaic systems (AVD) emerged with panels which could be steered in real time according to the needs of plants. Shading at the right time is not that easy with the risk to either miss a hot event and cause serious and irreversible injuries to the plants or shade too often, and impact carbon production. In this paper we present first an experiment with measurements of leaf temperature at different positions of grapevine canopy for two summer days in 2020 and 2021. Then, the energy balance sub-model part of a crop model that simulate plant growth for fruit trees and vines grown in heterogeneous AVD environments is presented. Finally, after having evaluated the coherence of the model with experimental results, the relevance of a mechanistic model to steer solar panels and protect plants from heat is illustrated through several examples. The heterogeneity of temperature within the canopy observed in the field experiments related with different variables such as air and ground temperature, leaf orientation and self-shading was correctly reproduced by the model. This work indicated that canopy temperature could be more integrative than a unique threshold of air temperature to take decisions on panel orientation to protect plants from heat stress.