A low-cost photovoltaic (PV) array monitoring system

The hardware and software design of a low-cost photovoltaic (PV) monitoring system are presented. The system was designed on ATmega8535 microcontroller and applied for PV array characteristics. The PV array characteristics monitored are solar irradiance, temperature, short-circuit current, open-circuit voltage, maximum power, voltage and current at maximum power, fill factor and also efficiency of PV array. The system uses a Pyranometer LI-200 for solar irradiance sensor, an LM35 for temperature sensor, a simple voltage divider for the voltage sensor, and a shunt resistor for the current sensor. The software was developed using Visual Basic (VB).