But the project is not just about electricity and economic benefits – the stakes are far higher. Regional security, ecological stability and the future of one of Asia’s great rivers all hang in the balance.
How big is the mega dam?
When completed, the project will overtake the Three Gorges Dam as the world’s largest hydropower dam. It could generate three times more energy with five cascade hydropower stations – an estimated annual capacity of 300 billion kilowatt-hours (kWh) of electricity, more than Britain’s total annual power output.
It is estimated to cost around 1.2 trillion yuan (US$167 billion), dwarfing many of the biggest infrastructure undertakings in modern history at around five times the cost of the Three Gorges Dam and even more expensive than the International Space Station.
Why is it important?
The project was first announced in 2020 under China’s five-year plan as part of a broader strategy to exploit the hydropower potential of the Tibetan plateau, with feasibility studies dating back to the 1980s. Beijing authorised the dam’s construction in December 2024.
