Green hydrogen, it is fair to say, is having a moment, with a number of new initiatives recently being announced. The EU plans to invest $430 billion in green hydrogen by 2030, while countries such as Chile, Japan, Australia and Saudi Arabia are all making big investments into the technology. And in February it was revealed that Portugal will start producing green hydrogen by the end of next year, and already has €10 billion of investment earmarked for eight separate projects.

So, what exactly is green hydrogen? Well, let’s start with hydrogen. Hydrogen is the first element you will encounter in the periodic table and is the lightest element of all. And despite there being more hydrogen in the universe than any other element, its atoms need to be “decoupled” from the other elements with which they occur. And it is  how this decoupling is done which determines how sustainable hydrogen energy is.

More than 95 per cent of the hydrogen currently used for energy is produced through “steam methane reforming” of fossil fuels which uses a catalyst to react methane and steam, which produces hydrogen. That process also produces carbon monoxide and carbon dioxide, and results in so called grey hydrogen. It’s a process that also results in 830 million metric tons of CO2 emissions each year (roughly the same as the UK and Indonesia’s annual emissions combined) which is why it is so important that green hydrogen is developed so that the Paris Agreement goals are met.

The bad news is that zero carbon or ‘green’ hydrogen is more expensive to extract than the traditional ‘grey hydrogen’ method of using heat and chemical reactions to extract hydrogen from fossil fuels. Green hydrogen is produced using renewable energy to ‘split water’; a process called electrolysis, although at the moment, less than 0.1 per cent of hydrogen is made this way.

Last year, seven of the world’s biggest hydrogen producers launched the ‘Green Catapult’ initiative, which aims to accelerate the scale and production of green hydrogen fiftyfold, in order to halve the current cost of hydrogen to below $2 per kilogram. Analysis by the Hydrogen Council suggests that a $2 price would result in green hydrogen becoming the fuel of choice in multiple industries including shipping and steel production.

One of the big benefits of hydrogen is that it can be stored in fuel cells, – essentially huge batteries – which means it is a more reliable source of energy than renewables such as wind and solar. While fuel cells can operate independently from the grid, they can also be connected to the grid in order to generate power.

Pound for pound, hydrogen also contains almost three times as much energy as fossil fuels. Due to its lightness (57 times lighter than gasoline fumes), hydrogen needs to be cooled to -253˚C to liquefy it, or it needs to be compressed to 700 times atmospheric pressure so it can be delivered as a compressed gas. 

Last year, the European Commission released a Hydrogen Strategy, which reported that “analysts estimate that clean hydrogen could meet 24 per cent of world energy demand by 2050, with annual sales in the range of €630 billion,” but there is a lot of work to be done.

In 2019, IRENA published a report about hydrogen’s green energy potential, which gave some reasons to be optimistic. The report said that while “a hydrogen-based energy transition will not happen overnight” and that the “need for new supply infrastructure could limit hydrogen use,” that dedicated hydrogen pipelines have existed for decades and “could be refurbished along with existing gas pipelines.”

The big issue is cost. Most of the technical issues are surmountable, and indeed, every year 70 million tonnes of hydrogen gets shipped around the US alone, so a lot of the infrastructure exists. However, hydrogen currently costs three times as much as natural gas in the US, and the production of green hydrogen is more expensive than producing ‘grey’ hydrogen as electrolysis is expensive (although it is getting cheaper).

This is why it is vital there are government supports, which is why Portugal’s announcement is so important. Portugal’s Environment Minister Matos Fernandes told Reuters that: “By the end of 2022, there will certainly be green hydrogen production in Portugal. Green hydrogen will, over time, allow Portugal to completely change its paradigm and become an energy exporting country.”

With other countries launching even more ambitious plans – China, for example has announced it aims to produce one million fuel cell vehicles by 2030 – the hope is that technologies will mature and the scale of the proposed projects should see costs fall. However, as IRENA said in a 2018 report, while hydrogen could become a key element of 100 per cent renewable energy systems, “The right policy and regulatory framework remains crucial to stimulate private investment in in hydrogen production in the first place.”