Billionaires are not known for doing things by half. When Elon Musk set up a battery plant, he billed it a “Gigafactory” and made unfulfilled promises that it would be powered entirely by its own renewable generators. When Roman Abramovich bought himself a yacht, it was a battleship-sized monster with two helipads and its own submarine.

The temptation to go big or go home applies in Australia as much as anywhere else. Two of the country’s richest men, iron ore billionaire Andrew Forrest and Atlassian software mogul Mike Cannon-Brookes, have spent years working up plans for a renewable project in the country’s far north that is a veritable thicket of superlatives — $30 billion to build the world’s largest solar power plant, backed up by the world’s largest battery, supplying Singapore with electricity via the world’s largest and deepest submarine power cable.

Infrastructure is an industry that rarely rewards mould-breaking boldness, and sure enough Sun Cable fell into administration earlier this year after its backers failed to reach consensus over how to advance the project. A consortium led by Cannon-Brookes’ family office is now in final talks to buy the assets after seeing off rival interest from Forrest’s Squadron Energy vehicle.

Both men are worthy of praise for putting their voices and money toward a vision of an Australia that can thrive in a world transitioning to clean energy, rather than clinging on to its status as the fourth-biggest exporter of fossil fuels. Sun Cable, however, seems to suffer from a bad case of billionaire’s disease. Less grandiose ambitions would do far more to nudge the world toward zero emissions.

The hurdles facing international energy projects are immense, with challenges in terms of both engineering, politics and finance. A speed hump on just one of those axes is normally enough to doom a multi-billion dollar piece of infrastructure, and Sun Cable struggles on all three. Its 4,200 kilometre submarine power cable is about six times as long as the current record holder, which links the UK and Norway under the shallow waters of the North Sea. It would go about twice as deep and 10 times as far as the SAPEI line between mainland Italy and Sardinia, currently the deepest undersea power cable. That stretches the limits of current technology.

Politics is a further issue. Singapore, the target customer, has shown little interest. The country, which owes much of its current wealth to its investments in some of the world’s biggest oil refineries in the 1960s, has long been distinctly sceptical about renewable power, and was one of the last major economies to announce a net-zero target last year. The city-state’s cool relations with its immediate neighbours, Malaysia and Indonesia, make a back-up supplier in Australia sound attractive from an energy security point of view. But that appeal is vastly diminished when you consider how the destruction of the Nord Stream 2 pipeline illustrated the ease with which undersea power infrastructure can be destroyed.

Renewable power hasn’t yet found a way of bridging Australia’s remoteness from the world. A nation long ruled by the tyranny of distance will face the same constraints in the net-zero era.

All those contribute to the financial issues. Australia has some of the world’s most competitive renewable power, but building any sort of major development in the remote north of the country lifts costs immensely — just ask Chevron Corp., which ended up spending $US54 billion on its Gorgon LNG export venture, $US17 billion over plan. First-of-a-kind subsea transmission cables don’t come cheap, and the losses that such a long wire racks up along its route — probably in the order of 15 per cent to 20 per cent — mean that much of that low-cost Australian renewable power ends up being wasted, pushing up the cost of the electrons that make it to Singapore.