Internet of Things System for Solar Resource Monitoring

Photovoltaic (PV) solar energy is a sustainable and clean source of energy that uses solar radiation to produce electricity. Although an environmental friendly source of energy, it is prone to irregular variations due to atmospheric factors that can cloud the Sun. That is why data acquisition systems (DAQ) are required to monitor closely these atmospheric changes, be they even short lasting. This paper proposes an Internet of Things (IoT) data acquisition system used for solar resource monitoring. In order to ascertain the performance ratio (defined as the produced energy divided by the potential available energy) of a solar plant, meteorological measurements are required. Among these atmospheric parameters, the global horizontal irradiance (GHI) quantifies well the potential energy that can be harvested from the Sun, and can be obtained using a pyranometer. Along with a low-cost All Sky Imager (ASI) used for sampling sky images with a frequency of one minute (for dataset building) for short term irradiance prediction, and a Raspberry Pi 4B as the central computing unit, a low cost IoT system is constructed. This data acquisition system for monitoring solar resources can be used in a PV power plant to analyze and potentially predict short term irradiance variations caused by cloud cover.