Some embodiments include a kit for supplying solar power in a battery-powered or fuel cell powered unmanned aerial vehicle (UAV) by incorporating flexible solar cells into a component of a UAV, affixing flexible solar cells to a surface of a UAV, or affixing flexible solar cells to a surface of a component of a UAV. The kit also includes a power conditioning system configured to operate the solar cells within a desired power range and configured to provide power having a voltage compatible with an electrical system of the UAV. Another embodiments include a solar sheet configured for installation on a surface of a UAV or on a surface of a component of a UAV. The solar sheet includes a plurality of solar cells and a polymer layer to which the plurality of solar cells are attached.