Economics: manufacture renewables to build energy security

China's rise to become the world's largest power producer and source of carbon emissions through burning coal is well recognized. But the nation's renewable-energy systems are expanding even faster than its fossil-fuel and nuclear power. China leads the world in the production and use of wind turbines, solar-photovoltaic cells and smart-grid technologies, generating almost as much water, wind and solar energy as all of France and Germany's power plants combined1. Production of solar cells in China has expanded 100-fold since 2005.