The influence of weather conditions on performance of photovoltaic modules

Abstract

This paper presents an analysis of the main weather conditions, meaning solar irradiance, ambient temperature, wind, rainfall, snow layer occurrence and pollution as well as their influence on efficiency of different kinds of solar modules. Mathematical models used to determine a solar cell temperature depending on the ambient temperature, solar irradiance and the speed of wind are presented. The impact of every factor on the photovoltaic cell temperature was established based on a few models. The results were as follows: ambient temperature affects cell temperature linearly, an increase of 1°C results in solar cell temperature’s rise of approximately 1°C. The linear dependency is also observed in influence of solar irradiance, a 100 W/m2 increase causes a 1,75-3,1°C rise of a photovoltaic cell temperature, depending on the chosen model. The wind impact however is not linear and it is a weather factor causing a positive outcome for a solar cell temperature – by increasing wind speed by 1 m/s, the average decrease of the temperature of a solar cell was defined in a range from 0,6 to 2 degrees Celsius, depending on the model used to determine it and more significant decrease of temperature was observed with lower values of wind velocity. The impact of temperature change of a PV module on change in solar energy conversion’s efficiency was determined for a chosen solar module available on the market. A linear dependency between efficiency and temperature was observed. An average decrease of efficiency depending on the photovoltaic panel ranged from 0,68 to 0,73 percentage point for every 10°C increase of module’s temperature in case of solar irradiance of 1000 W/m2