Photovoltaic performance assess by correcting the I-V curves in outdoor tests
Adelaida María Ibarra Padilla, C.D. Londoño, Franklin Jaramillo, I. Tovar, Juan Bernardo Cano, Esteban Velilla
Abstract
The photovoltaic performance is conventionally defined at Standard Test Conditions (STC), considering mainly an irradiance of 1000 W/m2 and device temperature of 25 °C. Nevertheless, outdoor conditions involve additional variables, including their transient behavior, affecting the performance. Therefore, measuring the performance at STC in outdoor tests is not always possible. In order to estimate the performance at STC or other power rating conditions such as the Nominal Operating Cell Temperature (NOCT), this work translated the outdoor performance at the target conditions by combining three different I-V curves and corresponding weather data for three photovoltaic technologies. Hence, a random process was proposed to generate the dataset to be translated, ensuring reliability in the estimation due to the significant number of considered weather conditions combinations, covering a wide range of the outdoor performance behavior as a function of irradiance and temperature. Besides, the dataset was filtered using an irradiance and extrapolation range, improving the estimation by calculating relative error of less than 8% at STC and NOCT concerning the datasheet values. Finally, the procedure was extended to estimate the temperature coefficients allowing a complete performance validation concerning the datasheet.