The proposed solar farm, near Tennant Creek, would be the world's biggest by a comfortable margin. It would stretch as far as the eye can see, across an area equal to more than 20,000 soccer fields.

Despite Cannon-Brookes's self-deprecating description of the project as "batshit insane", it could actually make technical and economic sense. And it's not the only mega-renewable energy project being pursued by credible Australian companies with the aim of powering the many hundreds of millions of people living to the north of us.

The scheme is a long way from a done deal, of course. Its commercial and technical challenges are enormous, and with a $20 billion price tag it would be one of Australia's largest ever construction projects.

But people who know the man behind the project - David Griffin, chief executive of Sun Cable - talk in glowing terms about his ability to take an empty paddock and convert it into a power station fuelled by wind or sun. Most recently he sewed up a deal to provide Australia's second largest employer, Coles, with 10 per cent of its electricity from solar. As one former colleague says, whenever Griffin encounters a barrier - and there are plenty ahead - he manages to "go round, go over, or ... blows [it] up."

So how can Griffin go from powering a tenth of Coles to powering a fifth of Singapore? In terms of technology, it's not a big jump. The Tennant Creek farm will use the same type of solar panel, just a heck of a lot more of them.

One difference, though, is that the project will use an ingenious Australian-made technology to simplify and accelerate the installation of the panels. An Australian company, 5B, in conjunction with former car-parts supplier IXL, will assemble the panels into a concertina-style kit in factories in Darwin and Adelaide. When they arrive at Tennant Creek, a forklift will simply unload and unfold the concertinas to create rows of panels arranged in A frames facing east or west.

Unlike the alternating-current system that transports the vast bulk of Australia's electricity around the country, the cable to Singapore will use what's called direct current, which will minimise the loss of electricity over those thousands of kilometres. While it isn't common, this technology is already deployed at different sites across the globe, including under Bass Strait.

Beyond Tennant Creek, two other mega-renewable energy projects plan to take advantage not just of Australia's superior solar resources but also of our world-class supply of wind. Both are located in Western Australia, one in the Pilbara and the other further south near Kalbarri.

These projects are very much in line with the opportunities Ross Garnaut spells out in his recent book, Superpower: Australia's Low-Carbon Opportunity. Australian renewable energy can become "a path to low-cost reductions in emissions in the rest of the world" in three ways, Garnaut writes: by supplying electricity directly to south-east Asia; by using electricity from wind and solar plants to convert water into hydrogen and shipping this to energy-resource-poor countries in Asia; and by using both electricity and hydrogen from renewable energy to process ores into metals (or batteries) for export.

Garnaut sees the third of those options as Australia's biggest opportunity. Producing metals in Australia saves on transport costs because we already produce a large proportion of the world's metal ores. Refined metals weigh much less than ore, but are worth significantly more. Garnaut's partnership with a British steel tycoon, Sanjeev Gupta, to revive the Whyalla Steel Mill and build an energy company backed by renewables is an effort to realise this vision.

What makes these projects possible is the rapid decline in the cost of wind and solar, along with further reductions in battery and hydrogen processing costs. It's this new reality that has the potential to slice through the Gordian Knot holding back Australian climate policy.

Senior policymakers, including many on the Labor side, have long seen emissions-reduction efforts as an economic threat. Consequently, Australia has not only been reluctant to implement emissions-reduction policies at home, we've also tried to sabotage efforts to get other countries to reduce their emissions.

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Yet it turns out that aggressive efforts by governments overseas to push down the cost of wind and solar have delivered Australia a potential competitive edge. To take advantage of this new reality, though, we need other countries to accelerate their efforts to increase the scale of battery and hydrogen technologies and reduce their costs. And we need them to enact the tighter emissions controls that will accelerate their shift to renewables.

In Australia, meanwhile, the alliance between fossil-fuel producers and industrial manufacturing has broken down. While manufacturing industry associations were busy helping fight the Renewable Energy Target and the carbon price, energy companies were planning the price increases that would make the impact of the carbon price look like a rounding error.

Manufacturers' only hope for energy price relief turns out to be the fuel source - renewables - that their lobby groups fought against so fervently. Meanwhile, mining companies - unless they're digging up coal - are also looking to cheap wind and solar to improve their competitiveness. This includes Twiggy Forrest's own iron ore mine, plus several mines in remote Australia extracting gold, silver and zinc.

Until recently the environmental movement and the Labor Party have tended to talk about solutions to climate change in terms of policies like emissions trading or renewables targets. What many are coming to realise is that they should be talking about specific projects they want to build.

For a voter in Gladstone or Townsville, an emissions-trading scheme sounds suspiciously like something that makes a banker in Sydney rich. And shutting down a mine - well, that sounds like it'll end in a dole queue. But imagine if tradies and labourers across central and north Queensland were shown a plan to repower mining and industrial plants from Gladstone up to Townsville and through to Mt Isa with a combination of hydro, wind and solar projects linked by new transmission lines. That would sound like employment and cash.

Some steps have already been taken. By 2021, the contribution of renewables to Australia's electricity supply will have risen from 15 per cent to 30 per cent in just five years. A number of major manufacturers and mining companies are signing up to new renewable energy projects to lower their energy costs. And partly thanks to Malcolm Turnbull, Scott Morrison and Liberal state energy ministers, the energy storage and transmission projects already under way can take the country well beyond 50 per cent renewables.