Hydrogen continues to generate waves of political support, with €25billion of US taxpayer money now available for new hydrogen hubs and demonstration projects.
However, its inexorable rise comes with a cautionary note.
As many commentators are reporting – see articles from The Guardian, New York Times and Grist – while hydrogen will clearly contribute to the future clean energy mix, the way in which future hydrogen is produced, and the focus of its end use, will have a major bearing on its ability to actually reduce emissions.
Without clear guidelines on future clean hydrogen production, governments risk spending billions propping up hydrogen production facilities with enormous carbon footprints, wiping out many of other climate gains.
Greater education is also required to dismantle a misleading ‘hydrogen for everything’ narrative, with many applications benefiting more quickly and substantially from other solutions such as direct electrification and batteries.
At this pivotal moment in the hydrogen revolution the public purse must be invested wisely in research and projects which avoid wasting time, money and resource.
The nature of hydrogen production
One of the greatest challenges with creating hydrogen is the high energy requirement. Due to the thermodynamics involved, it is simply costly in energy terms to produce. The very small molecule is also notoriously hard to handle, which bring practical challenges. To become a major player in our decarbonised future the dirtiest forms of hydrogen production, using fossils fuels, quickly need replacing with renewable energy to create ‘Green’ hydrogen.
Currently, more than 90% of the world’s hydrogen comes from coal and gas, classed as ‘Brown’ and ‘Grey’ hydrogen respectively. This type of production is described as ‘super-polluting’ releasing CO2 and unburnt fugitive methane into the atmosphere.
Another derivation known as ‘Blue’ hydrogen is also produced using gas, with the distinction of CO2 being captured and stored underground. However, this process creates higher methane emissions compared to ‘Grey’ hydrogen, which warms the planet faster than CO2, in order to power the carbon capture.
By contrast, ‘Green’ hydrogen is created using electricity from renewable energy – such as wind, solar and marine energy – and is by far the cleanest form of hydrogen production.
Hard to abate sectors which cannot be electrified
For decades, hydrogen has primarily been used by the chemical, agricultural and refining industries to produce ammonia, fertilizers, and methanol. It is also heavily adopted in the hydrocracking process by refining industries to create petroleum products, including gasoline and diesel.
Other sectors with a long history of hydrogen use include Food, Metal working, Welding, Flat Glass Production, Electronics Manufacturing and Medical.
Now, newly commercialised applications of hydrogen, like fuel cells, are opening all kinds of opportunities in transportation and other energy-related industries, including Space Exploration, Aviation, Global Logistics, Public Transportation and Power Generation.
However, with electricity generated by renewables being a scarce resource, future clean hydrogen projects are best geared towards hard-to-abate sectors which cannot be electrified directly. This is because direct electrification and batteries offer more in terms of carbon reduction, and much more quickly.
The Clean Hydrogen Ladder provides insight on future use cases in order of merit.
In order to maximize carbon reduction, we suggest that the world should invest massively into making all existing hydrogen usage Green, while focusing on new applications with highest merit (‘the hard to electrify cases’). This will require huge volumes of renewable electricity, even without including cases that are unlikely to become competitive such as heating homes or mainstream transportation.
Hydrogen is only Green when there is Green electricity – the case for 24/7 renewables
Another important element in the creation of Green Hydrogen is the requirement for producers to match operational power demands with renewable energy resources on an hourly basis. Since electrolyser facilities are chemical plants with high CAPEX, they achieve best economics if they can operate 24/7. This is a challenge if the electricity supply relies solely on wind and solar, with periods when the wind doesn’t blow and the sun doesn’t shine.
Wave energy offers significant benefits helping achieve this 24/7 matching requirement, being a consistent and complementary energy source helping to stabilise the renewable electricity mix, ultimately allowing Green hydrogen facilities to run at higher utilization and lower cost.
With 500-1800GW or 2500-7000TWh available along the coast of industrialised countries, wave energy is seen as a key success factors contributing to a 100% renewable energy system due to its complementary production profile with wind and solar.
In addition, with available hydro potential heavily exploited and nuclear having a hard time to deliver electricity at a competitive cost, a diversified mix of renewables will ultimately provide the most competitive and sustainable alternative for 24/7 clean electricity grids and Green hydrogen production. Adding wave energy to the mix can significantly reduce the total capacity in generation, storage and grid required to match supply to 24/7 demand, thereby reducing the cost and accelerating the transition to a net-zero future.
Case in point – Green Hydrogen to Green Steel
The unique role which wave energy can play in the Green Hydrogen process was recently outlined in a new study by CorPower Ocean, Instituto Superior Técnico de Lisboa (IST) and a global green steel manufacturer.
The report specifically demonstrates how wave energy, with its consistent production profile, can support 24/7 clean electricity generation. The graphic below illustrates how wave energy can enable Green Hydrogen plants to run at higher utilization to make green steel by 2030, with close to 50% reduction in installed capacity and a 25% reduction in the cost of electricity.
It’s an especially positive result, showing how the ever-evolving clean hydrogen production process can support hard to abate sectors like the steel manufacturing industry, responsible for around 7% of global greenhouse emissions.
As momentum inevitably grows – and with a further $100bn expected to be paid out in uncapped tax credits for US hydrogen projects over the coming decades – greater attention must now be paid to the type of hydrogen revolution we really want.