Could Australia, one of the world’s biggest exporters of coal and natural gas, become a solar superpower? The island continent, distant from Asia’s megacities, plans to capture the plentiful Outback sun, store it in giant batteries until nightfall and transmit it to Singapore along a watermelon-width cable traversing 2,800 miles of seafloor, including a deep trench. The Australia-ASEAN Power Link, which is part-owned by two Australian billionaires and was endorsed last month by the Australian government, may be the most ambitious renewable energy project underway anywhere. And it could mark a new chapter in the history of energy: the intercontinental movement of green power.

Eventually, the project’s backers believe that Australia eventually can supply cheap solar power to a pan-Asian electricity grid, lifting living standards for millions of people and reducing the region’s dependence on coal and natural gas, which are big contributors to global warming.

Scheduled to start operating in 2027 at a cost of about $16 billion, the project would combine the world’s largest solar farm, the largest battery and longest submarine electricity cable. It would produce three gigawatts of power, the equivalent of 9 million rooftop solar panels.

The specifications are so complicated that it will be designed by computers using artificial intelligence, according to David Griffin, a solar and wind farm builder who said he came up with the idea while driving through Australia’s hot, dry interior.

Undersea challenges

The project, owned by a company called Sun Cable, is driven by geopolitics as much as physics. The Association of Southeast Asian Nations (ASEAN) has discussed a regional power grid for 15 years — Europeans have shared electricity for five decades — but the talks have been frustrated by political differences and infrastructure gaps.

With no natural sources of energy, cloudy skies 80 percent of the time and two much bigger neighbors — Malaysia and Indonesia — long envious of its wealth and social stability, Singapore is looking for reliable, cheap energy that does not contribute to global warming.

Safe, peaceful and sunny Australia could be the solution. Separating the two countries, though, are thousands of miles of ocean, the Indonesian archipelago and the 10,000-foot-deep Sunda Trench.

Sun Cable would be six times as long. The sea floor along the route will have to be mapped in precise detail by sonar. Over the total distance, some 4 to 10 percent of the electricity would be naturally lost along its speed-of-light journey, depending on the design of the cable, engineers say.