Just when you thought wind and solar would dominate electricity supply for the next hundred years, along comes Alan Finkel to kick off the Australian Clean Energy Summit with a rousing hymn to hydrogen.

That’s not to say he’s down on wind and solar – “two fantastic technologies” – but the storage job required to calm their erratic generation is too big to be filled by what’s in the toolkit (pumped hydro and batteries).

“If we’re going to replace oil, coal and gas with solar and wind, it’s doable, it’s an opportunity,” Australia’s chief scientist said. “But it’s a massive challenge.”

Last year, solar and wind contributed 1.2% of global energy needs. To push coal and gas out of the picture, 70 times more solar and wind capacity will need to be built. “It’s a massive, massive challenge.”

An enormous amount of storage will need to be built, be it batteries or pumped hydro. “But it’s going to need at least one more thing,” he said. “Many people, not just me, will argue we will need a means of storing electricity in a high-density transportable form … and the leading candidate for doing that is hydrogen.”

Ready for export

Hydrogen can be made using clean energy to separate water into its constituents, where the oxygen is released and the hydrogen bottled. 

Export-scale hydrogen production is a fair way over the horizon, but Finkel likes to think ahead. Imagine a world 20 to 30 years from now, he said, where Australia is exporting as much hydrogen – produced using only solar – in energy terms that it currently produces as LNG exports. Hydrogen has 2.4 times the energy density of LNG, he said, and if you assume energy losses of 50% in manufacturing and transmission, the equivalent to in exports for 2018 of LNG would be 30 million tonnes of hydrogen.

That amount, when it reaches market, would be converted into 980TWh.

“To make that, I need 1,980TWh,” he said, which is eight times more than the total generation in Australia in 2018 – or about 900GW of solar. “It’s huge … really huge. About 18,000 square km of solar. But you know what? That’s only three-quarters of one giant cattle station. If you think of it that way, it’s a manageable task.”

Rising global power

That’s if you want to match Australia’s LNG exports for 2018. What if you want to aim higher?

The Hydrogen Council is predicting in 2050 the world will be using 667 million tonnes of clean hydrogen a year. It will take about 44,000TWh of solar to make that, or 180 times Australia’s total energy generation in 2018. All up, that’s about 400,000 square km of panels. “Which is, on a global scale, not that much,” Finkel said, as some in the audience gaped.

OK, so the scale is a lot to take in. What about diversity of supply? “I don’t know about you, but it scares me to think of a future where we’ve only got two primary energy sources – wind and solar.”

Is there a third source? Wait for it…

“Hydrogen from coal and natural gas is something that has to be given consideration,” he told an auditorium filled with clean energy professionals.

“Can we do it? It’s a question. I don’t know.”

Caught and stored

Carbon capture and storage would need to work to make it happen, and so far the technology is a long way from economical. “If it could be done properly … it would give us a third primary energy source.”

If Australia wants to exploit a full realm of resources to produce hydrogen, we’re not alone: Russia, Norway and Qatar are already looking at fossil fuels as raw materials for hydrogen production. To ensure we stay competitive, Finkel has developed a national strategy in cahoots with the COAG Energy Council Hydrogen Working Group.

“If we get it all right, I think 100 years from now it would not be unreasonable to imagine we would still be occupying a beautiful planet.”