IoT embedded systems network and sensors signal conditioning applied to decentralized photovoltaic plants

The proposed Internet of Things (IoT) monitoring network aims at reducing costs associated with commercial dataloggers and sensing modules, requiring control and data storage that need proprietary software. Other usual drawbacks of commercial solutions are limited sensor connections with low expansion flexibility, maintenance restricted to the manufacturer and long cable communication distances. Our developed IoT network was implemented and tested in three grid-connected photovoltaic (PV) plants, installed in Fortaleza and Maracanau, in Brazil, and Cologne, in Germany. The proposed IoT embedded systems are based on free software, allowing online distribution, free usage and communication with a server in the Cloud wirelessly via WiFi. A web page called Web Monitor was developed for online data consultation and for real-time monitoring of the three plants. PV modules temperature monitoring has the objective of providing data for the analysis of electricity generation efficiency and for detecting failures characterized by overheating of the PV plant. Meteorological data such as solar irradiance, ambient temperature, relative humidity and wind speed are also monitored, allowing a more complete analysis of the effect of these variables on the PV module's performance. Hence, we propose the design and development of an IoT modular system to compose a worldwide monitoring network focused on meteorological and PV modules temperature data, available to researchers from partner institutions. (C) 2019 Elsevier Ltd. All rights reserved.