We are developing a solar powered system (SPS) on LAPAN Surveillance UAV - 03 (LSU-03). It is developed for marine monitoring to support marine security from illegal fishing. A longer time is needed to optimize the monitoring missions. This is strongly supported by Indonesia's sunlit lands throughout the year so long-distance targets and wide area coverage can be achieved. The total power required is 96 Watts per hour. Therefore, it is very important to fulfill the power to fly for 6 hours. The solar powered system consists of solar module, maximum power point tracking (MPPT), and battery. The system development is to regenerate the power. A hardware design and terrestrial measurement of SPS is presented. It was conducted in Aeronautics Technology Center - LAPAN, Bogor. According to the results, the development of solar powered system gave 12.76 percent efficiency. The I-V graphics and battery charging time is presented. The SPS was able to charge the battery 8 Ah for 60 minutes. Therefore the SPS satisfy the power requirement for LSU-03 onboard electrical system.