The country's wind power capacity will rise to 30,000 megawatts from 12,000 megawatts, Shi Lishan, deputy director of renewable energy at the National Energy Administration, said in Rudong city in the eastern province of Jiangsu today. China's wind power capacity was the fourth-largest in the world last year, according to Shi. Investment in alternative energy may exceed 2 trillion yuan by 2020, the National Development and Reform Commission, China's top economic planner, said in 2007. Wind power is "vital" as it is the cheapest form of renewable energy, Shi said. About 80 percent of the country's power is produced from coal.