Scientists are researching whether so-called solar chimneys, with a height of half a kilometer or even higher, might produce enough clean energy to help reduce China’s chronic air pollution. A test plant is running successfully in Inner Mongolia and scientists want to build full-sized versions in cities such as Beijing and Shanghai. The researchers have suggested the towers could be constructed inside new skyscrapers. The technology involves covering an area of several square kilometers to create a greenhouse around a high chimney. The hot air produced in the greenhouse rises through the tower, driving turbines that generate electricity. The higher the tower, the stronger the updraft and the more power created. The highest previous attempt to master the technology, which has been discussed for decades, ended in failure when a 195-meter tall tower in Manzanares, Spain, collapsed in 1989 due to structural failure. But Professor Wei Yili, the leader of the project at the Inner Mongolia University of Science and Technology, said he was confident they could now build safe and efficient towers higher than a kilometer. The 50-meter high test “solar updraft tower” has been running in the Gobi desert in Wuhai for nearly four years. The project has managed to generate up to 4,800 kilowatt-hours of electricity a day. One design integrates the solar tower into a high-rise building. “Many Chinese cities are considering the construction of buildings more than 500 meters high, but have met strong resistance due to their high cost and energy consumption. The updraft tower will make a skyscraper ‘green’ and strengthen its physical stability as well,” Wei said. “If all new high-rise buildings are built with updraft towers, large cities’ demand for coal-fired power plants will be significantly reduced, air quality improved, and smog reduced.”