The world is entering a new energy era marked by concerns over energy security, climate change, and access by the poor to modern energy services. Yet the current energy path is not compatible with sustainable development objectives. Global demand for energy will continue to grow; so will CO 2 emissions. Achieving a low-carbon energy world will require an unprecedented technological transformation in the way energy is produced and used. That transformation has begun, as renewables capacity continues to grow, prices continue to fall, and shares of global energy from renewables continue to increase. Government policies are the main driver behind renewable energy's meteoric growth. Still, the world is tapping only a small amount of the vast supply of renewable energy resources. There is broad consensus that the role of these resources should be expanded significantly in order to meaningfully address energy security, energy access, and climate change.