Solar panel plays a major role in the renewable energy sector. Unfortunately substandard and unspecified solar panels are seen now a days in the market of many countries. Furthermore, solar panel testing equipment is not available everywhere and is a costly device. So, to fulfill customer rights and to know the efficiency of the solar panels, a simple portable solar panel efficiency measurement system has been designed and developed. The system includes a single Ardunio Uno, a voltage sensor, a current sensor (ACS712), a multi meter and a lux meter. The measurement has been taken under real sun conditions. The system determines maximum voltage (V max), maximum current (I max), maximum power (P m), fill factor (FF) and efficiency (η) of the solar panel. The system reveals that the efficiency of a 10 W, 8 W and 0.65 W silicon solar panel are 9.65%, 8.59% and 8.4% respectively.