The Influence of a Photovoltaic Module Thermal Model Choice on the Error of Calculating the Module Performance

Abstract

The purpose of this work is to determine the error introduced into the values of the temperature of a photoelectric module and the power generated by it by using one or another method of accounting for its heating (thermal model) in the calculation. The existing thermal models of photovoltaic modules and their comparison are reviewed. Even the simplest models can calculate the temperature of an open rack mounted photovoltaic module with an error of less than 20°C and the power it generates with an error of 2–3% in climatic conditions that do not coincide with the conditions of its development. Complex unsteady thermal models can only be used to a limited extent, not only due to the complexity of their implementation. Being theoretical, based on the thermal balance equations of a module, they require experimental verification, at least for the selection of formulas for calculating heat transfer coefficients, which greatly complicates the task. In addition to the methods of accounting for module heating, there are more significant sources of calculation errors: dust and dirt on the module surface along with others. The choice of a thermal model of a photovoltaic module is not critical from the viewpoint of calculation error of the generated power, all the most popular thermal models give approximately the same result.