The chapter mainly introduces the unique wireless power transmission system of SSP. Microwave wireless power transmission and laser wireless power transmission are the two transmission methods currently considered in the SSP scheme. Microwave power transmission is suitable for high-power transmission from space to the ground. It needs to go through the DC-RF, microwave transmission, RF-DC three main processes and includes space and ground segments. The space segment is mainly used to efficiently convert electricity into microwaves and use large-scale transmitting antennas for high-precision transmission to the ground. The ground segment receives the microwave beam and converts it into electricity efficiently. In order to achieve high-precision microwave power transmission, it also includes pilot beam emitting on the ground and pilot beam reception and processing in space. The design of microwave power transmission system mainly focuses on microwave frequency, system efficiency, beam accuracy, and system scale. The laser wireless power transmission system mainly consists of a laser source, laser transmission and beam direction control device, laser receiving and conversion device. Because the laser transmission beam is narrow, the corresponding transmission and receiving devices are small, the direction control is flexible, and it is suitable for medium and low-power wireless power transmission that makes it have various possible applications, such as supplying power to the spacecraft, drone, airship, and lunar rover.