The electric energy converted from solar energy is the energy of spacecraft in orbit. However, different from ordinary spacecraft, the candlestick experimental cabin is equipped with a pair of "soft wings"-flexible solar panels, which have been upgraded in terms of volume, power generation and environmental adaptability. The photoelectric conversion efficiency is as high as 30%, and the weight is only half of that of traditional solar cells.

The solar panel of candlestick experimental module adopts flexible triple junction gallium arsenide solar cell array technology, which consists of hundreds of thousands of flexible solar cells. Hui Yu, deputy director of the Space Energy Division of Electric Energy (18 Institute), said that the veneer thickness of these flexible solar cells is less than 1 mm, which can be described as "as thin as paper". The weight per unit area is only 50% of that of traditional solar cells, and the photoelectric conversion efficiency exceeds 30%, reaching the international advanced level. After series-parallel connection, the solar array can continuously provide energy for the spacecraft.

The flexible solar panel of candlestick experimental module adopts a unique design structure, which is like a folded accordion during launch. Rigid housings at both sides fold and compress the flexible substrate with solar cells. When the power generation is increased by 3 times, the folding volume of solar cell array is also reduced by 20% compared with the traditional solar cell array.

The battery panel has achieved "slimming" and the supporting parts have to be "pressed" into a plane. According to the requirements of the mechanical environment of the launching section of the solar array, the researchers designed and developed a thin isolation diode module and an ultra-thin lightweight mesh flat cable, which effectively ensured the surface flatness of the solar array.

However, when the panel is in orbit, it will continue to be exposed to various threats such as strong radiation and atomic oxygen, and it will undergo more than ten high and low temperature cycle tests as high as 80 degrees Celsius and as low as-1 10 degrees Celsius every day. In order to provide better protection, researchers put on a coating as thin as micron, and at the same time broke through technologies such as high-voltage electrostatic protection and alternating fatigue buffering at high and low temperatures, which verified that the battery life was increased to 15 years.