Planes, trains and ships. Cars, buses, and lorries. Boilers, hobs and heating. Furnaces, refining and fertilisers. This is a zero-emissions, clean hydrogen fuelled wish-list. Many will indicate that hydrogen could power and produce the vehicles, items and utilities just listed. Many will push and lobby behind hydrogen as a godsend fuel source.
However, how much can we really expect from this fuel? Though we are in a run-in in reaching net-zero nationally and internationally, hydrogen has limitations. It has a place in combatting climate change, but perhaps not to the extent some seek.
The Colours of Hydrogen
While hydrogen itself is a clean fuel, the method by which it is produced is not necessarily free of carbon emissions. Methods of production are colloquially referred to by the colours: grey, blue, and green. Other methods and colour labels exist, however these three are the most common.
Green hydrogen refers to hydrogen produced with electricity by electrolysis to split water. Importantly, the electricity supplied must be generated from renewable sources, such as wind power and solar, which produce no or relatively low emissions when operational.
Green hydrogen production is the goal. Currently only 1% of global hydrogen supply is green. And so, the scale up required for it is immense just to meet current major hydrogen fuel uses, in oil refining and ammonia production, let alone the increase in hydrogen consumption that will occur in the next decades in homes, transport, and electricity. This is as the International Energy Agency (IEA) and UK government foresees.
Electrolysis today is expensive, of relatively low efficiency, and has scaling-up doubts. Despite this, this low-carbon method of production is on the rise and capacity for it is projected to increase significantly. Earlier this year, Dubai saw the launch of the first green hydrogen plant in the Middle East region. During Expo 2020 Dubai, taking place October 1 2021 until March 31 2022, scale-up and storage for green hydrogen is to be demonstrated.
Blue hydrogen may be worse for the planet than the use of natural gas
On the other side of the hydrogen coin, is both grey and blue hydrogen. Both refer to production methods that come from fossil fuels, chiefly natural gas. These methods such as steam methane reforming, generate carbon emissions.
Grey hydrogen is the most cheap and abundant production method of hydrogen, and so global emissions are significantly added to. Blue, however, differs from grey in that it relies on the use of carbon capture technology. This reduces emissions to the atmosphere due to the carbon dioxide being captured and stored underground.
Globally, carbon capture projects are increasing and many are to be operational throughout the decade. The UK has carbon capture projects ongoing, such as through the ‘Northern Endurance Partnership’, where some of the world’s largest oil, gas and energy companies are working to decarbonise the Humber and Teesside industrial clusters. In the Humber region, Equinor has the blue hydrogen project ‘H2H Saltend’ in the pipeline, while BP is pushing forward with its plans for the UK’s largest (blue) hydrogen facility in Teesside.
However, a recent report, by Cornell and Stanford universities, has cast doubt on the effectiveness of blue hydrogen at reducing emissions. In fact, it states that blue hydrogen may be worse for the planet than the use of natural gas. This is due to both the efficiency of hydrogen fuel, and the potential for leaking and venting of extra methane needed for blue hydrogen production.
Depending on where you stand on hydrogen use, the climate issue and your work, this report divides opinion. Critics of blue hydrogen exist. Those who believe it to be an obstacle in tackling green hydrogen’s own supply chain and cost issues, may have just been handed a reason to support their critiques. This is despite some describing blue hydrogen as the transition method from grey to green, and the IEA itself having blue hydrogen production at 38% of the total for 2050, in its ‘Net Zero by 2050’ roadmap.
Critics of the report equally exist too. Equinor, whose portfolio in (blue) hydrogen production and storage are growing, reportedly does not agree with assumptions and conclusions drawn in the report. The UK’s long awaited hydrogen strategy was published on the 17 August 2021, and the funding and backing given to blue hydrogen is, thus, controversial. For now, they describe a ‘twin track’ approach for green and blue hydrogen, supporting both, though have left it till 2022 to give further detail on production strategy.
The Potential Uses of Hydrogen
All colours of hydrogen produced may undergo power generation in a fuel cell, where the hydrogen reacts with oxygen in the air to produce water only, and no carbon emissions. Of those transport, industry and home matters listed in the introduction, there is debate about whether hydrogen has a place to fuel them all.
Airbus has described hydrogen as the ‘next frontier in aviation technology’
Altogether transportation accounted for 16.2% of global greenhouse emissions, in 2016. In the same year, transport became the UK’s largest source of emissions, at 28%. And with transport, hydrogen fuel cells face their rival – lithium-ion electric batteries. Electrification drastically reduces emissions when the electricity is supplied by renewable sources.
While these batteries have their own sustainability issues, they are preferred for use in cars, with battery-powered cars outnumbering hydrogen fuel-cell electric vehicles (FCEV) by millions. Some will say that there is no rivalry, but the opportunity for both technologies to complement each other.
Hydrogen power, though inefficient in comparison to batteries, is likely to play a role in decarbonising heavy-goods vehicles (HGVs), aeroplanes, trains, and buses. This is because the size/number of batteries required for larger vehicles would be too high and heavy.
With hydrogen, these vehicles could get a similar driving range and refuelling speed as conventional internal combustion engine vehicles. For this, there will need to be a ramp up of hydrogen fuel cells, fuelling stations and storage tanks.
Aerospace company Airbus has described hydrogen as the ‘next frontier in aviation technology’. Hydrogen is the most energy efficient during flight per unit of mass in comparison to both battery and conventional jet fuel technologies. Airbus has three concept planes in development which combine burning liquid hydrogen fuel and fuel cells for electricity in a gas-turbine engine.
Aircraft is just one side of the story; airports would equally have to change for hydrogen refuelling if this is the course of action over biofuels. Nevertheless, the IEA expects behavioural changes from us, such as forgoing regional flights in favour of trains where possible, for net-zero by 2050.
There are millions of pounds of government funding assigned in its strategy for hydrogen
Travelling is as key to life as the home. Houses and other buildings could benefit from hydrogen through heating. Although here, it is argued that hydrogen gas heating is less efficient in comparison to electric heat pumps and strong insulation. The pumps have relatively high upfront costs, though are cheaper than hydrogen boilers to run.
Though, heating products company Worcester-Bosch has a hydrogen-ready boiler in the works. Hydrogen can be delivered in some pipelines that transport natural gas; however, the safety considerations must be assessed too.
In the newly published government’s hydrogen strategy, the government establishes that it is working with the Health and Safety Executive, and Ofgem to assess safety, through trials and research. A government decision on this will be made in 2026, which could potentially lead to hydrogen being used for powering cars, heating homes and cooking. Hydrogen’s potential in industry for steel, shipping and furnaces is also promising.
There are millions of pounds of government funding assigned in its strategy for hydrogen. Banking on blue hydrogen as much as green hydrogen may have uncertain results going forward, especially considering Cornell and Stanford’s new research. As the government has deadlines to meet over this decade listed in its hydrogen strategy, we may see necessary changes to hydrogen plans in order to reach net-zero.
Although, in the coming years it is clear blue hydrogen storage and production projects led by major oil, gas and energy companies will continue. It is the transitional effort which keeps them involved before green hydrogen costs will come down. For now, perhaps the most interesting part of the strategy is whether the government can bring these costs down for hydrogen. Just like, in its own comparison, to the UK’s successful offshore wind sector.
Featured Photo courtesy of pennjohnson via Flickr. Image license found here. No changes were made to this image.
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