A $167 billion power project promotes Chinese self-sufficiency while unsettling neighbors downstream. HONG KONG—China has begun the construction of a giant hydropower project at the earthquake-prone edge of the Tibetan plateau, a spectacular engineering feat that is central to Beijing’s enduring mission to become self-sufficient in critical areas such as energy.

The $167 billion facility will require digging tunnels that plunge through high mountains to harness the power of a river that sharply descends through the deepest and possibly longest canyon on the planet.

If its planners succeed—after shrugging off objections from neighbors—the project could generate triple the output of the world’s largest hydroelectric facility, China’s Three Gorges Dam, which is big enough to power around 40 million Chinese homes.

The endeavor is a dramatic example of China’s determination to become self-reliant in areas of national importance, from technology to food, a years long campaign that has gained momentum as Beijing’s rivalry with the U.S. intensifies. China imported nearly a quarter of its energy supply in 2023, a level of dependency that Beijing is working hard to undo.

The plan, slated to be the world’s most expensive infrastructure project, will also plow money into a struggling Chinese economy and bring jobs and business to a remote and sensitive corner of China where Beijing is trying to engineer the loyalty of the Tibetan population.

A planned $7 billion high-voltage transmission network will deliver electricity from the site in Tibet to Guangdong province, the economic center on China’s southeast coast, and the cities of Hong Kong and Macau.