It’s all very well to decarbonise the electricity sector but a zealous pursuit of hydrogen might be disproportionate to requirements, write Graham Palmer and Josh Floyd.
The hype cycle, introduced by the research firm Gartner in 1995, is used to describe the progression of an emerging technology from its initial “innovation trigger” to its eventual influence in a market or a domain. Central to the cycle is the initial enthusiasm of proponents and the media. Enthusiasm contagion drives research and deployment funding. A race for commercial leadership ensues, drawing in positive reporting from consultancies and other actors seeking to capitalise on the bandwagon effect, creating a positive feedback loop.
Eventually commercial reality kicks in, leading to a waning of interest and a refocusing by firms on core activities. Ideally, the knowledge captured and the infrastructure built provides a foundation for a sustainable and profitable industry.
The dot-com bubble from 1994 to 2000 is a case study of hype then fortunes lost, but which left behind the physical networks and software architecture of the internet that we have today. Similarly, the 19th century British and American railway manias funded physical rail networks that were to survive financial speculation and crash.
It is not hard to imagine the current wave of enthusiasm for hydrogen conforming to the hype cycle. The development of a “hydrogen network” could be compared with the mid-19th century development of Britain’s railway network. The railway network operated in parallel, but also linked in with, the road, inland canal and sea-based transport networks that preceded it. It therefore both substituted for and complemented the existing transport networks. Similarly, we would expect hydrogen to link in with, and complement, value chains that are currently serviced by the petroleum, natural gas and electricity networks.
The overall effect of rail transport was to significantly improve the efficiency and availability of freight and people movements. The comparative advantages of fixed networks for heavy transport persist today – inland bulk commodity haulage and inner urban rapid passenger movement.
With respect to hydrogen, we can expect the comparative advantages relative to other energy carriers to be strongly associated with its versatility and storability. But unlike early rail, hydrogen-based solutions are competing with economically entrenched, incumbent fossil-based solutions.
We’ve seen this before
The pursuit of a renewably powered “hydrogen economy” implies a dual electrification-hydrogen strategy, entailing an efficiency-versatility trade-off. Grid electricity is highly energy efficient, but dependent upon relatively inflexible networks and therefore less versatile than fuels – hydrogen is highly versatile and portable, but much less efficient.
We have already seen two periods of hydrogen hype before – the first being the post-Apollo mission enthusiasm for hydrogen of the early 1970s, and the second being the Japanese and American enthusiasm for fuel cell vehicles from the late 1990s to the early 2000s. In neither case did hydrogen deployment reach sufficient scale to leave a residual hydrogen network. So how should we think about the current wave? Will deployment cross a critical threshold? Is this time different?
In our recent book, Energy Storage and Civilization, we don’t seek a decisive answer to the question of how hydrogen technologies will evolve – instead we step back to examine the foundational role of energy storage in economic systems and let readers form their own conclusions. Our aim is to reframe the role of storage and allow questions for further exploration.
We seek to challenge the dominant frame of reference that storage can be understood in technological terms alone, with its value defined solely in techno-economic terms and solely determined by profit-seeking actors.
According to the thesis proposed in our book, across history the forms of human social organisation recognisable as civilizations share, as a common enabler, the storage of their primary energy sources on a large scale. The levels of socio-political complexity achieved in the societies most people inhabit today are enabled by abundant and cheap energy.
But these societies are shaped also by the means of energy storage made possible by the physical characteristics of our principal primary energy sources. Energy storage is essential to the exercise of both physical and political power. It allows the distribution and control of power in time and space over large territories.
We argue that each distinct form of large-scale, socio-politically complex society evident in the historical record can be identified with a universal and ubiquitous form of energy storage, beginning from the Neolithic, through the period of industrialisation and into the Age of Petroleum.
The fundamental role of energy storage can be inferred from the ways in which it is coupled with political power structures, and from its relationship with institutions as essential as monetary systems. Today, petroleum, the energy stock most central to the control of physical economic activity, provides the de facto primary physical backing for the global monetary and trade system. Energy storage and its relationship with human societies must be appreciated simultaneously in biophysical and cultural terms, alongside the more familiar technological and economic ones.
Following from this historical perspective, we posit that future human social forms recognisable in today’s terms as civilizations will similarly be dependent upon suitable energy storage technologies and media. This affords the investigation of energy storage a status that we think is quite a bit more interesting than the typical techno-economic treatment implies.
The historical trend is towards fuels with a higher hydrogen-to-carbon ratio, of which pure hydrogen produced using renewable or fission/fusion primary energy sources is the natural end point. But a hydrogen economy is neither inevitable nor likely to deliver energy more cheaply than we are accustomed to.
If history provides a reliable lens through which to envisage future change trajectories, societies may choose to bear the increased costs that this implies. If so, then this will necessarily involve trade-offs elsewhere, and so it is likely that such societies will take significantly different forms to those familiar in the rich, industrialised world today. For example, electric and hydrogen-based mobility may imply a shift towards micro- and shared mobility, rather than a straightforward substitution of suburban-based petroleum-fuelled SUVs.
An outstanding question for energy transition is: why hydrogen? Visions for the complete decarbonisation of energy usually start with decarbonisation of electricity. Given the rapid cost declines of wind and solar, there is optimism that much of the heavy lifting can be accomplished with a geographically diverse suite of wind farms and solar plants, with strategic investment in storage.
Electricity, though, comprises roughly a third of global energy use, having taken 50 years to double its share. Although a conversion towards increased electrification is under way, there are many energy services provided by fossil fuels that will difficult to switch to electricity.
Three examples illustrate the extent to which a perspective on energy transition and energy futures centred on wind plus solar plus electrical energy storage inadequately characterises the nature and scale of the challenge faced in a complete departure from fossil-fuelled economies.
Ammonia: First, world annual supply of ammonia is currently around 172 million tonnes. Ammonia (NH3) is essential for nitrogen fertilizers and many industrial chemical compounds. About one-third of the protein in humanity’s diet depends on synthetic nitrogen fertiliser, an amount that is forecast to increase significantly. Nearly all ammonia is currently produced via the Haber-Bosch process in which atmospheric nitrogen is reacted with hydrogen gas in the presence of a catalyst at high temperature and pressure. The hydrogen for this is currently produced via steam-methane reforming or coal gasification. In a fully renewable future, this hydrogen would also need to be produced via electrolysis.
Green steel: Second, world annual steel production is currently a little under 1.7 billion tonnes. Nearly all reduction of iron ore to pig iron, to enable further processing to produce steel, is carried out using coal as a chemical reductant and heat source. It is technically feasible to reduce iron ore using hydrogen, with heat supplied by hydrogen combustion or direct electrification. Significant development challenges should be anticipated, though.
Shift to EVs: And third, there are currently about 1 billion passenger vehicles in the world. Rapid replacement of those vehicles with battery electric drive trains, with range equivalent to current internal combustion engine vehicles, would mean a rapid increase in the annual demand for several minerals. Annual demand for lithium, cobalt, nickel and graphite would vastly exceed the current annual supply of those minerals, and in some cases significantly surpass globally economically recoverable reserves. The embodied energy of producing the batteries alone would represent a sizable fraction of global primary energy demand. Furthermore, with a very rapid shift to EVs periodic turnover of the global vehicle fleet would imply boom and bust cycles for key inputs at 10- to 20-year intervals.
There is always a cost
In summary, fossil fuel resources are a one-time-only inheritance, simultaneously the source of our prosperity and a fundamental enabler of the degradation of our planetary life-support systems.
While electrification of energy services will be an essential part of a post-carbon civilisation, hydrogen-enabled solutions will be essential to fully realising such an ideal.
Green hydrogen-based solutions are already commercially available. However, at the macro-scale a hydrogen economy will almost certainly require greater expenditures on energy, as a proportion of total economic activity, than has been typical since the latter part of the 20th century.
Human societies will very likely need to re-examine demand expectations, and indeed the wants and needs fulfilled by current energy demand, that have taken shape in the context of copious on-demand power.
Graham Palmer is a research fellow at Monash University. He has published in the area of biophysical economics, renewable energy, life-cycle analysis and energy-economic modelling. His current research interests include the future roles of energy storage systems.
Joshua Floyd is energy, systems and society fellow at The Rescope Project. His work draws on training and experience in futures studies and strategic foresight, and systems thinking and practice.