Microcontroller Based Data Acquisition System for the Study of Shadowing on a Photo Voltaic Modules

A Microcontroller is a programmable device that may also be used to control other electronic devices such as a stepper motors, Light Emitting Diodes (LED), etc. Another class of modern microcontrollers, which has gained momentum, is the Arduino. Arduino Uno Microcontroller is used in this research that is proposed to study the impact of shadows on solar arrays. In this research, the Arduino Uno was selected based on its lower cost and less power consumption. The system includes two 1 W, 5 V solar panels as sensors. The first of the two panels is used as a reference and is placed in a clean un-shadowed area, and the second one is a test solar panel that is mounted in the area that has been designated for the placement of the Photovoltaic (PV) array. This Arduino Uno based Data Acquisition System (DAS) features a micro Storage Disc (SD) card, a real time clock (RTC) and a software algorithm developed for data collection purpose. The developed Arduino software algorithm uses the irradiance received by the two mentioned solar panels to calculate the Solar access. Solar access is the ratio irradiance affected by shadowing to that irradiance without any effect of shadowing. The Arduino stores the time-stamped resulting records onto its mounted SD card as a Comma Separated Value (CSV) file for viewing and analysis in MS Excel. In Excel, graphs showed that a solar panel or a PV module is affected by shadowing. The irradiance of received PV modules decreases when shadowing of any kind occurs on their surface.