The S4000 flying wind system completed in Yueyang, China's Hunan province, its first test in an urban context. The 67-metre-long, 40-height and 23-metre-wide structure is a platform filled with helium designed to carry light generators up to 4,000 meters, where the winds are stronger and more regular. The electricity produced is transmitted to the ground through the anchor cable, with a voltage of between 10 and 35 kilovolts. The test verified t…