China has started construction of the world’s biggest hydroelectric dam, a project that’s set to be far larger than the Three Gorges Dam — already the world’s biggest single source of green power — and more expensive than the International Space Station.

China's Premier Li Qiang announced construction had begun on what will be the world's largest hydropower dam, located on the eastern rim of the Tibetan Plateau and estimated to cost around $170 billion,

The Indian and Bangladeshi governments fear the project could have major impacts on millions of people living downstream.