This class of UAV depends on solar power to meet its long flight time requirements. Solar power systems rely on the use of maximum power-point tracking (MPPT) circuitry to ensure that solar energy is harvested at the optimum voltage before conversion to a voltage suitable for charging a secondary battery, or delivery to the power systems intermediate bus network. As this class of UAVs develops, high-efficiency power-conversion topologies such as zero-voltage switching and zero-current switching (ZVS/ZCS) which are used in Vicor BCMs are important to enable the widening variety of fuel sources and applications with increasing power challenges.