DUNHUANG, China — As the United States takes its first steps toward mandating that power companies generate more electricity from renewable sources, China already has a similar requirement and is investing billions to remake itself into a green energy superpower.

Through a combination of carrots and sticks, Beijing is starting to change how this country generates energy. Although coal remains the biggest energy source and is almost certain to stay that way, the rise of renewable energy, especially wind power, is helping to slow China’s steep growth in emissions of global warming gases.

A series of projects is under construction on the nearly lifeless plateau to the southeast of Dunhuang, including one of six immense wind power projects now being built around China, each with the capacity of more than 16 large coal-fired power plants.