Distributed thermoelectric model of a PV module: effect of inhomogeneous boundary conditions

The scarceness of the available sites for classical ground mounted due to the low power density of solar PV lead to the emergence of new PV systems with the aim to resolve the conflict with residential and agricultural needs as part of the SGD 7. Precise modeling of PV performance necessitates knowledge of the cell’s temperature, and predicting this temperature becomes progressively more challenging due to their new design features, impacting the yield and therefore their return on investment. The existing thermal models that have been developed for conventional PV systems have several limitations, which lead to mitigated cell temperature estimations. Several studies show a varying distribution of convective heat exchange coefficient (h-coeff) on the PV installation depending on its geometrical configuration This implies the necessity to explore more advanced thermal approaches.

In this communication we introduce a coupled 5-layer inertial physical finite-volume model that incorporates a local distribution of h-coeff as input. It includes a 2D thermal model coupled to an electrical model in 2 ways, the first coupling resides in the classical thermal effect on the cell’s efficiency and the second coupling considers the electrical connection layout of pv cells. The model is developed using opensource libraries such as PVlib and will be validated first numerically and experimentally. Numerically, by being compared with the validated sandia 1-layer model. Experimentally, using several controlled experiments on a single module and using data from PV installations deployed by TotalEnergies. These validations will be conducted with a constant h-coeff since it requires a developed model to estimate its spatial distribution. Indeed, this work constitutes a bridge towards a more detailed CFD model for PV installations.

Not focusing on the calculation of the h-coeff, as a first step, we will estimate the electrical power loss due to the non-homogeneous h-coeff distribution that will affect the electrical production in two ways, first by reducing the overall DC power and secondly by impacting the AC conversion efficiency due to voltage drop caused by thetemperature increase .