News of a new 345 km, $380B underwater electricity cable linking Australia’s mainland with Tasmania is just the latest in a booming submarine power market.
The Tasmanian project—or the Marinus Link—will help share renewable energy, but the high voltage cables which can can carry up to two gigawatts or more of electricity have been a force in the world’s power market for decades, one that is seeing explosive growth as the world electrifies.
As many as 161 strands of copper—the preferred material—form the core and are wrapped together in bundles of three before being encased in polyethylene insulation, jacketed in plastic and lead, and armoured with a metal sheath to help withstand the tough marine environment.
While the cables may be complex and expensive to make, and laying them in trenches up to 16 feet deep something of a logistical challenge, they offer the benefit of sharing power more directly between countries or entire continents in a single conduit that is also out of sight.
The technology isn’t new. The first underwater cable to carry electricity was laid in the early 1800’s, but the world’s first submarine HVDC Cable—Gotland 1—was installed in 1954 between the Swedish mainland and an island 94kms away.
But underwater power cables have evolved since then to significantly increase boost their design, capacity and length. The world’s longest inter-connector is currently the 580km long cable between Norway and the Netherlands with a capacity of 700MW.
That may soon pale in comparison with Australia’s proposed undersea electricity project known as the Australia-Asia Power Link or Sun Cable. Despite some corporate upheavals plans to transmit solar power via a 4,300 km, high-voltage direct current submarine cable from the Northern Territory to Singapore by 2030 and Indonesia some time later remain in place.
The world is already girded by hundreds of submarine cables, but projects are expected to soar given growing demand for electricity for data centres, electric vehicles and clean energy like offshore wind or solar. It may be out of sight, but copper is quietly fuelling a greener, smarter world.
Global Submarine Cable Map: https://www.submarinecablemap.com/
