A thermal model for open-rack mounted photovoltaic modules based on empirical correlations for natural and forced convection

Abstract

This paper proposes a thermal model for calculating the temperature of open-rack mounted photovoltaic (PV) modules taking into account the meteorological conditions, position (i. e. the inclination of one PV module and the angle between its surface and wind direction) and technical characteristics of the PV modules. The present model is valid for the steady-state operation and is based on the energy balance equation in which the forced convection is modelled by the new empirical correlations. The possibility of occurrence of the flow separation along the surfaces of the PV modules is included in these correlations. The effect of the angle between the wind direction and the PV module plane, which is usually ignored in the modelling of forced convection, is also taken into consideration. In this manner, it is possible to estimate the temperature of PV modules more precisely, as well as to determine the power and efficiency which depend on the temperature. For four particular PV modules, it is found that the temperatures, obtained using the proposed thermal model, are in good agreement with the corresponding measured temperatures. Compared with the other models commonly used for thermal analysis of PV modules (SNL and NOCT-based correlations), this model yielded better results. The deviation of the PV module temperature calculated using the proposed thermal model from the measured one is up to 2 °C, and the deviations of the PV module temperatures calculated using the SNL and NOCT-based correlations from the measured ones amount up to 5 °C and 20 °C, respectively, depending on the PV module type and ambient conditions.

Predicting solar power and energy production over the course of a full day

“…The results showed that some of the models were more adapted to different weather. Alternatively, Perović et al 25 choose to develop a thermal model for open rack mounted PV module based on empirical correlation for natural and forced convection. The model included inclination of the PV module and wind direction, in addition to other meteorological conditions.…”

Experimental Validation of a Thermo-Electric Model of the Photovoltaic Module under Outdoor Conditions

“…In addition, two other models for determining the temperature distribution in the PV module and the output power are included. The temperature distribution in the PV module was calculated using the Ansys Transient Thermal software package, and the already confirmed empirical equation [10,[24][25][26][27][28][29] was used to calculate the output power of the PV module. In addition to validating the presented dynamic thermo-electric model, the importance of accuracy of measuring devices and optical losses is also included.…”

Simulation Study to Predict Generation Power of a Vehicle Photovoltaic System

“…The CFD simulation study of the threedimensional flow fields around the photovoltaic cell is also suitable for studying the power generation efficiency of low solar radiation conditions and the influence of surface contamination on photovoltaic cells' power [10][11][12]. Perovic et al proposed a thermal model to model the temperature of photovoltaic cells according to the meteorological conditions, the locations of the photovoltaic cells, and their technical characteristics and determined their power and efficiency with consideration of their predicted temperatures [13]. Zhiqiang and Dongyang proposed a neural networkbased photovoltaic power prediction model based on the Hilbert transform and frequency entropy to solve the problem that the power fluctuations from photovoltaic power stations affect the dispatch operations and stability of the power grid incorporating substantial percentages of photovoltaic power [14].…”