Implementation of a low-cost data acquisition system for “PROPRE.MA” project

A low-cost monitoring system for grid-connected PV system is presented. It is based on an inexpensive and available hardware, as well as easy software which does not require any high specific skills and which can be written in different programming languages (C/C++, python, etc). The proposed system uses a 16-bits resolution with a good accuracy and enough reliability responding to the most IEC standards requirements on PV applications. It is composed of a group of sensors measuring meteorological parameters (Solar irradiance, ambient temperature, wind speed and direction) and module temperatures while electrical parameters (currents and voltages in both sides, DC and AC) are numerically taken from the inverter. The collected data are first conditioned using precision electronic circuits, processed by the PcDuino board, and then stored in an SD card in a form that can be easily used, not requiring any external computer. The system allows local storage and distance data transfer through Internet. The PV system users are informed about its operation and each incident is reported by an e-mail message generated by an error notification routine. The proposed architecture can be built easily; it has low energy consumption and enough flexibility for potential future modifications. The system has been installed to monitor 20 outdoor grid-connected PV systems more than one year ago and all its units operate in a satisfying manner.