China's high-altitude wind power technology has achieved a major breakthrough, as the domestically developed S4000 Stratosphere Airborne Wind Energy System (SAWES) recently completed a test at a base in Northwest China, CCTV News reported on Saturday.

An upgraded version of the earlier S2000 SAWES, and the successful completion of its full-process flight validation marks the transition of China's stratospheric high-altitude wind power technology from the iterative development phase toward the engineering deployment phase, according to the report.

The test covered the entire process of ascent, station‑keeping, power generation testing, and smooth recovery, with all indicators meeting the required standards, fully verifying the system's reliability in complex and extreme high‑altitude environments, the report said.

As an upgrade from the S2000 model, the S4000 adopts a new configuration with significantly improved overall performance. Its maximum operational altitude reaches 4,000 meters, making it suitable for deployment in the vast majority of regions across China.

It can directly adapt to mainstream grid power supply requirements and has a design service life of up to 20 years.

Unlike conventional low-altitude wind turbines, which are often referred to as "windmills," the system employs a flying device.