The Hydrogen Hype (All Over Again): A More Realistic Perspective on the Future of the Hydrogen Economy

Hydrogen’s role in the energy sector has oscillated between periods of enormous hype and subsequent doses of cold realism. Initially touted as the cornerstone of a future clean energy economy, hydrogen, particularly when derived from renewable resources, has been celebrated for its potential to offer zero-emission energy. However, a more in-depth examination reveals complexities and contradictions, challenges, ironies, and inefficiencies that offer a very different picture of the place of hydrogen in a future sustainable energy landscape.

In the late 1990s and early 2000s, the first hydrogen bubble was inflated by expectations that hydrogen, primarily through fuel cells, would revolutionize energy consumption, especially in transportation. Governments and industries invested heavily, envisioning a rapid transition to a hydrogen-based economy. However, by the mid-2000s, this enthusiasm had deflated owing to technological, infrastructural, and economic barriers, not least being the realization – which frankly was obvious from the start – that hydrogen’s environmental benefits were completely undercut by its predominant production method from fossil fuels, mostly natural gas (in the West).

Even today, the majority of hydrogen is produced via Steam Methane Reforming (SMR), still using natural gas, leading to very significant carbon emissions. SMR, which produces what is sometimes called ‘grey’ hydrogen, starkly contrasts with the environmental purity of hydrogen often trumpeted by the hydrogen industry. Without effective carbon capture and storage (CCS), which in itself is a highly questionable operation, to produce so-called ‘blue’ hydrogen, SMR completely contradicts the goal of reducing greenhouse gas emissions, highlighting a core irony in current hydrogen utilization.

In theory and occasionally in practice, hydrogen can be made by cleaner methods, but there is another Achilles’ Heel of hydrogen, which is inscribed by the laws of physics: inefficiency. The overall efficiency of hydrogen, from its production to end-use, is almost invariably disappointingly and wastefully low. Most significantly, hydrogen’s lifecycle efficiency trails well behind direct electrical transmission and use. While ‘green’ hydrogen production via electrolysis promisess environmental friendliness, it is marred by substantial energy losses at various stages, including electrolysis, compression, storage, and reconversion to electricity. These inefficiencies are pivotal in assessing hydrogen’s viability as a sustainable energy carrier.

Mention of hydrogen as an energy carrier brings up another vital point: hydrogen, unlike say natural gas, its nearest competitor, is not an energy source, because it does not occur naturally on Earth in significant or usable volumes. Thus it has to be made and that takes huge resources. Saying that free, elemental hydrogen is abundant because it makes up 75% of the (non-dark) mass of the universe is useless and distracting – it is simply not true here where we want to use it.

There are yet other ways of making hydrogen, most of them as bad as or worse than grey hydrogen, forming a confusing rainbow of colours: hydrogen can be produced by nuclear-reactors, with all their unsolved toxic waste problems, by either thermochemical water splitting or eletrolysis, and this hydrogen can be known as red, pink or purple; turquoise hydrogen comes from methane pyrolysis (thermal decomposition in an inert atmosphere); brown or black hydrogen from coal gasification; yellow hydrogen is made using solar power to electrolyse water; and white hydrogen occurs naturally in underground deposits, but there are currently no known economic methods to retrieve it if it is even there in quantity. It should be noted that despite all these colour labels, hydrogen is invisible, colourless, odourless and non-toxic so that it is undetectable by humans – sophisticated scientific instruments have to be used to find and monitor it.

There are also yet more well known serious problems that will always dog hydrogen. Firstly, it is extemely explosive, so that it will always need handling with the utmost care. Contrast this with petrol or diesel, which whilst they are obviously and necessarily flammable, produce staggeringly few accidents in fuel facilities and very few vehicles catch fire or explode, even when they are in collisions. Hydrogen also suffers from very low volumetric energy density, in other words, it takes a huge volume of hydrogen to do much work, which means in turn that one must employ extreme processes either to liquefy it at minus 253 degrees C, or hugely compress it to as much as 10,000 pounds per square inch; not only are these not simple processes, they both take lots of energy, special hardware and stringent safety measures.

Another well known and expensive problem is how to transport hydrogen in very large quantities; this almost invariably means using pipelines. If (green) hydrogen is replacing natural gas, why not just send it down the existing gas pipelines? Once again, physics is not helpful. Because hydrogen is both very small and has unusual chemistry, it is able to diffuse and dissolve into steel gas pipelines and cause them to become brittle and potentially crack, which will lead to leaking hydrogen, which is a very dangerous explosive risk. In fact, there are no easy or cheap solutions to the problem of transporting hydrogen at scale.

All of the above problems are varyingly serious and to greater or lesser extent are either fixable or at least can be mitigated or lived with if the demand is great enough. However, there is a new problem that is only just surfacing. New research suggests that hydrogen leaking into the atmosphere, which in practice it always does, may worsen the effect of certain greenhouse gases, specifically methane, ozone, and stratospheric water vapour, by amplifying their effect.* Thus, even though hydrogen itself is not a GHG, if its indirect global warming potential is nearly 12 (according to climate scientists at CICERO in Oslo), and if it is to be rolled out a massive scale, this indirect GHG effect could become very serious. That scale can be illustrated by the IEA’s projection that demand for hydrogen will increase sixfold by 2050 in order to reach net zero and McKinsey’s much bolder projection that by 2050 hydrogen “could contribute more than 20 percent of annual global emissions reductions”.** If hydrogen is proved to be a considerable indirect GHG, a major part of its raison d’etre would be seriously, if not fatally compromised. Estimates vary regarding the extent of hydrogen leakage, but it is highly likely to be worse than natural gas, possibly three times worse and as much as six per cent.***

As it became more and more obvious that sustainable energy was (and is) eluding us, the mid-2010s saw a renewed interest in hydrogen, now with a focus on ‘green’ hydrogen produced from renewable energy sources such as wind and solar power. However, despite technological advancements and growing economic and political support, like the founding of the Hydrogen Council in 2017, transitioning to a green hydrogen economy is daunting. Electrolyzers, though imporoving slowly, remain expensive, and the scale of renewable infrastructure required is absolutely colossal, demanding vast investments and facing potential societal resistance and regulatory challenges.

Hydrogen’s future most probably lies in its strategic application. It holds promise in sectors where electrification is difficult, such as in heavy industry and long-haul transportation. Here, hydrogen could be a useful component in a diverse energy portfolio. However, in the passenger vehicle sector, hydrogen competes with more established and more efficient battery electric vehicles, and faces immense challenges in infrastructure and will never entirely be able to overcome its energy efficiency problems.

Hydrogen’s potential as a grid storage solution, especially for long-term energy storage, may yet hold some promise in some niche areas. The power-to-gas-to-power process, converting surplus renewable electricity into hydrogen and back when needed, could be useful in regions with significant renewable generation variability. However, this application is not without its inefficiencies and will still require careful consideration within the broader energy storage landscape. In hydrogen’s favour, grid storage development is moving at a glacial pace compared to what is needed.

To a considerable extent, the journey towards a hydrogen economy looks like a road to nowhere, except in certain limited cases, so that while hydrogen looks good at first glance and does have potential in certain sectors, its widespread adoption is, and probably always will be, hindered by its own physics, inefficiency, being a possible indirect GHG, as well as by cost, danger, and infrastructural challenges. A realistic approach to hydrogen would involve recognizing its specific applications and integrating it within a broader green energy strategy, while ideally and in a more sensible world, trying to reduce overall energy consumption.

* The “deeply concerning” climate impacts of hydrogen leaks – New Statesman

** Five charts on clean hydrogen and net zero | McKinsey

*** Green Alliance and researchers at Columbia (see New Statesman article)