Experimental Approach of Photovoltaic System in Operation for Performance Prediction of Natural Convection

The main objective this paper is to assess the thermal model of the convective heat transfer from photovoltaic solar modules. Experiments were carried out in laboratory and in-situ conditions. Whereby the convective heat transfer in low wind speed was considered, while evaluating the relation between the classical and natural convective situations. The form as that system change heat with the environment causes impact in efficiency of the generation of energy. The energy balance is described by the incident irradiation in the photovoltaic modules and the forms that system converts that energy as irradiation, convection, conduction and generation of a potential difference. The classical problem of flat inclined plates was used to understand the behavior of the photovoltaics module. The existing correlations using dimensionless numbers, developed in experimental studies and numerical simulations, have limitations in their use and in many cases do not provide results that approximate a photovoltaic system in operation. In this work, an experimental bench was developed and placed in a natural convection chamber with a data acquisition system for temperature, voltage and current. The small-scale experiments allowed realistic estimation, for the assessment of the thermal performance in a real power plant configuration. The experimental data showed a suitable correlation, of more than 0.9, with the installed system, suggesting its capability to predict the behavior of the system.