Test of Different Instruments for Measuring that Current/Voltage Curve of Photovoltaic Modules

Abstract

Nowadays, there is a high demand for energy worldwide. Solar energy has emerged as one of the best renewable energy options to help meet global energy demands while helping to solve the climate change crisis. The rising demand for solar energy has prompted the massive production and widespread deployment of solar PV modules globally. Manufacturers, researches, engineers and solar installers use specialized instruments known as solar PV current/voltage testers or tracers to test and measure the current/voltage characteristics of Solar modules. Such measurement enables fault detection and performance problems in solar modules; however, they are very expensive and often inaccessible for institutions and researchers with low income. In certain cases, low-cost instruments are developed as alternatives to test solar PV performance issues. Performance problems in solar modules are caused by changes in the modules’ parameters such as series resistance, parallel resistance, ideality factor and saturation current density. Solar module parameters are very crucial but difficult to compute. Thus, the main goal of this study was to test both commercial and low-cost solar module current/voltage testers by measuring the current/voltage curves of solar modules and using the current/voltage data to calculate solar modules and cells parameters. The Werner plots were used along with the Origin software to evaluate solar module/cells parameters. The research results showed that the low-cost solar module current/voltage curve tester can compete with commercial current/voltage tester in terms of measuring series resistance, parallel resistance, saturation current density, etc. Furthermore, it was confirmed that the low-cost instrument can measure multiple solar modules at once, a capability that was lacking in the expensive commercial WaveLabs instrument. However, the commercial instruments were faster in measuring the modules current/voltage curve due to their short sweep speed (20-500𝜇𝑠) and (0.02-2s) respectively compared to a sweep speed of 6seconds for the low-cost instrument.