Thermal analysis of a ground-mounted photovoltaic system coupled with the crop of a metal-hyperaccumulating plant using multiple modelling approaches

Understanding the operating temperature of photovoltaic modules is crucial for assessing their electrical performance, yet most agrivoltaic models focus on crop yield rather than PV thermal behaviour. This study addresses this gap by proposing a one-dimensional dynamic thermal model based on a nodal approach to simulate the photovoltaic modules’ temperatures. The model was validated using photovoltaic back-surface temperatures and integrates soil and vegetation surface temperatures and meteorological parameters. This model (Model 3) was evaluated against two simplified thermal models: the Ross thermal model (Model 1) and the Normal Operating Cell Temperature model (Model 2). Model 3 showed the greatest precision with a Root Mean Square Error down to 1.6°C and a Nash-Sutcliffe Efficiency coefficient > 92 %, outperforming Models 1 and 2 by 20 % in Nash-Sutcliffe Efficiency coefficient and 50-80 % in Root Mean Square Error reduction. Model 1 performed better under cloudy conditions (Root Mean Square Error 3.6-4.5°C; Nash-Sutcliffe Efficiency coefficient 72-80 %), while Model 2 slightly improved sunny-day predictions (Nash-Sutcliffe Efficiency coefficient up to 82 %). Model 3 consistently provided the best results (Nash-Sutcliffe Efficiency coefficient > 92 %). Comparing simulated and measured electrical energy production of an opaque module, Models 1 and 2 overestimated output (+2 % to +3 %,), while Model 3 exhibited the closest agreement (deviation < 1 %). Parametric simulations with Model 3 highlighted the potential of brownfield sites in southern France for ecovoltaic deployment. This work provides a robust thermal modelling framework for ecovoltaic systems, improving performance predictions.