Researchers from Chongqing University, the China Academy of Space Technology’s Xi’an Branch, and Xidian University also in Xi’an have started construction of the first space base for an experimental solar power station in Chongqing. They plan to launch four to six tethered balloons, connect them with each other to set up a network at an altitude of around 1,000 meters. The balloons will collect sunlight and convert solar energy to microwaves beamed back to earth. Receiving stations on the ground will convert the microwaves to electricity which is distributed to a grid. The test facility will occupy 13.3 ha and demonstrate space transmission technologies while studying the effect of microwaves beamed back to Earth on living organisms. The engineers will need to resolve two major technical difficulties: accurate, directed transmission of high-capacity microwaves (so far possible over a distance of about 100 m only), and construction of a large space-based power station whose size and weight has yet to be determined. If these challenges can be tackled, a small to medium-sized stratospheric photovoltaic power plant will be built between 2021 and 2025. After 2025, larger-scale space photovoltaic power plant systems will be investigated. The long-term goal is to establish a Gigawatt commercial photovoltaic power plant in space by 2050.
CAS news release, February 26, 2019