Digital colorimetric sensing for real-time gas monitoring for smart green energy system

In this study, we demonstrate that a digital colorimetric sensor platform can transform a conventional energy system, such as gas-insulated switchgear (GIS) into a smart green energy system. Our sensor platform consists of a colorimetric sensor film (CSF), an array of silicon photodiodes, and a low-power-driven fiber optical photodiode with a wireless communication protocol integrated into an information network. The photodiode measures the transmitted light of the color-variable CSF when exposed to sulfur dioxide (SO2) gas, a decomposition by-product of the sulfur hexafluoride (SF6) gas in GIS. We report the electrical photocurrent measurement through the CSF can measure the concentration of SO2 gas via remote and real-time monitoring and shows a comparable behavior to UV-Vis absorption measurement. The limit of detection of the sensor, 0.78 ppm is sufficient to analyze the GIS insulation deterioration allowing green energy systems.