An Off-Grid PV Power System for Meteorological and Eddy Covariance Flux Station in Kranji, Singapore

This paper describes an off-grid (stand-alone) PV system for powering an eddy flux station on tropical grassland in Kranji (1°25'N, 103°43'E), Singapore. Eddy covariance flux systems are used to quantify exchanges of CO2, H2O and energy between the atmosphere and land. Our system includes gas analyzers for CO2 and H2O, and sensors for rainfall, wind speed, wind direction, long-wave and short-wave radiation, diffuse radiation, and soil heatflux. The off- grid PV system consists of eight 160Wp monocrystalline solar panels, sixteen 12 V deep cycle batteries, a charge controller, and an inverter. To monitor the performance of our off-grid PV system, we developed a Python program to communicate with the controller and inverter, and record data on a small single-board computer. We applied a Matlab program with meteorological measurements to predict the PV array output. The meteorological measurements and operating data of the PV system are presented and discussed here.