Unconventional and optimized measurement of solar irradiance in Bengaluru using photovoltaic techniques

Field solar radiation measurement is very essential to estimate the conversion efficiency of the solar photovoltaic (PV) system. Pyranometers, instrument used for solar radiation measurement are very expensive and require regular calibration and increasing maintenance cost. This paper provides an alternative low cost solution to estimate the solar radiation received on field. The paper addresses the design and development of MSP430G2553 microcontroller based data logger for measurement of the solar panel voltage and current output. The design is based on maximum power point tracking technique using 16-bit microcontroller to measure, analyse and compute the instantaneous maximum power of solar PV panel. The data is communicated through RS485 onto storage device for future analysis. The experimental analysis is carried out in Bengaluru co-ordinates. The estimated solar radiation is compared with recordings from a calibrated pyranometer. The loggers required very low power requirement and can be powered by the parent panel on which they are mounted thus avoiding requirement of grid. This feature makes it ideal for use in rural side field PV analysis. The developed SPV logger gives accurate measurement of solar PV output and aide in estimation of incoming solar irradiance.