Has hydrogen’s time arrived?

1975 is a useful starting point. That's the year of publication of a hefty book by Professor J O'M. Bockris, Energy the Solar-Hydrogen Alternative. Bockris was an internationally renowned electrochemist with a reputation made in the UK and USA. In 1975 he was here in Adelaide heading Flinders University's Institute of Solar and Electrochemical Energy Conversion.

Today that label would connect his Institute with climate change. Bockris had a different agenda, fossil fuel exhaustion. He did appreciate the value of both solar and nuclear as clean energy but mainly saw the solar/hydrogen combination as a way of replacing fossil fuels. Australia's renowned solar resource would provide primary energy as electricity. That electricity would be used in generating hydrogen by the process of electrolysis. The hydrogen could then be stored, distributed and used like fossil fuels. One of those uses would be conversion back to electricity.

With these ideas Bockris was advocating a worldwide solar-hydrogen economy. His vision and contagious enthusiasm became widely respected. Nearly 50 years later one can see that his inspiration did not gain the traction he sought but it definitely signalled a first wave of hydrogen interest.

A second wave started in the USA in the mid-1990s. Politically driven it was aimed at ending US transportation dependence on imported oil. That aim seemed technically feasible but hydrogen was expensive. Reducing its cost became the mission of a large US government program. One of its leaders, Joseph J Romm, published The Hype about Hydrogen in 2005. The title captures the mood of the times. It's also a spoiler alert. The program faded away.

However the second wave wasn't finished. In 2003 President George W Bush announced a $1.2 billion initiative for developing clean hydrogen-powered automobiles. Ford had already trialled a hydrogen-powered production model sedan and was promoting its Model U concept hydrogen-fuelled car. BMW was another developer of hydrogen-powered cars.

Hydrogen fuel cells were also of interest for powering electric vehicles. Fuel cells are like batteries except that their electrochemically active ingredients can be fed continuously; fuel cells are recharged with fuels rather than electricity. Though known for over a century, fuel cells started their serious development only around 1960 as part of the US space program. Transportation applications followed. Buses were an early target but over the years steady progress in fuel cell technology has enabled several car manufacturers to produce or trial fuel-cell powered electric passenger cars. Growth will call for future expansion of hydrogen refuelling outlets.

The current burst of hydrogen excitement amounts to a third wave. It has a fresh focus, the newly-branded product Green Hydrogen.While chemically identical to the "old" 75 million tonnes/year natural gas-based "grey" hydrogen, Green Hydrogen is made with renewable energy and zero carbon emissions. That's its critical feature, enabling it to spawn a new range of clean products and processes. Hence a value proposition like:

Green Hydrogen presents the opportunity to create new industries involving unlimited quantities of globally tradeable renewable energy and green products with a wide range of valuable industrial applications, all harnessing Australia's solar and wind energy resources.

There are already some specific targets. Former Australian Chief Scientist Dr Alan Finkel and environmental activist group WWF Australia both suggest a green hydrogen export industry that could eventually match or exceed present exports of liquefied natural gas. They estimate this would require clean electricity generation around seven or eight times Australia's present total national electricity output.

How credible is the Green Hydrogen vision? Is hydrogen frenzy perhaps distorting judgements? What does hydrogen's history tell us? It certainly suggests that hydrogen can induce unrealistic expectations. However, some signs are encouraging. For one, Australia is not alone in its Green Hydrogen ambition. Goldman Sachs projects a global hydrogen market of $1.4 trillion by 2050 with some 80 GW of installed hydrogen electrolysis capacity by 2030. Germany suggests it will have 108-350 GW renewables devoted to hydrogen electrolysis by 2050. Bavaria alone aims to spend 1 billion euros on hydrogen projects in the next few years.

So there are grand plans. But right now commercial production of Green Hydrogen is zero.

Some advocates seem to think that producing hydrogen by electrolysis will make it cheaper than the present product "grey hydrogen" made from natural gas. That looks improbable. More likely Green Hydrogen will be costlier. However by rights it should be a more valuable product and if it can command a higher price it might still be commercially viable.