XI'AN -- Chinese scientists have taken a major step toward building a space solar power station, a giant power plant in space that could one day send energy back to Earth or to spacecraft.

A research team from Xidian University in Northwest China's Shaanxi province has made significant progress on the Sun Chasing project, or "Zhuri" in Chinese. The team has developed a ground-based test system for wireless power transmission that can charge multiple moving targets at the same time.

In recent tests, the system achieved a wireless power transmission efficiency of 20.8 percent from direct current to direct current over a distance of 100 meters. It delivered 1,180 watts of power. The team has also built a wireless charging system for drones. In a test, a drone flying at 30 kilometers per hour was able to receive 143 watts of stable power from 30 meters away.

A space solar power station works exactly as its name suggests: a huge array of solar panels placed in orbit. It would collect sunlight in space, where the sun always shines, and then convert that energy into microwaves or lasers to beam down to Earth or directly to satellites and spacecraft. This could address two significant issues: supplying uninterrupted power for space missions and alleviating energy shortages on the ground.

In 2018, the research team launched the first phase of the Sun Chasing project to build a ground test system. By June 2022, they had completed the world's first full-link, full-system ground validation system for a space solar power station. Now, the team has moved to phase two. The goal now is to solve the challenges of generating high power in space and transmitting it efficiently over long distances.

According to Duan Baoyan, an expert at Xidian University and an academician of the Chinese Academy of Engineering, recent breakthroughs include improving the efficiency of solar energy collection and conversion, increasing the precision of microwave beam control to reduce energy loss, and making the transmitting and receiving antennas smaller and lighter, which is critical for space application.

The team has also solved the problem of how to power multiple moving targets at once using a single transmitter. This means that in the future, one space power station could potentially supply electricity to several satellites or ground vehicles at the same time, Duan added.

Duan noted that there is still a long way to go before a space solar power station becomes a commercially viable reality. The next step, he said, is to conduct in-orbit tests. He said that he hopes to contribute Chinese wisdom and solutions to global energy change and sustainable development.