China has broken ground on what it says will be the world's largest hydropower project, a $170  billion feat capable of generating enough electricity each year to power Britain.

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.

When asked about the possible downstream impact of the dam on Assam, he said it is not yet known whether it will be good or bad.