Hydrogen (H) is the most abundant element in the universe. It takes three quarters of the universe’s matter and 9.5% of the human body mass or approximately 90% of all atoms. However, it does not exist in nature by itself.
It combines with other elements and to produce it, its atoms need to be decoupled from them. The decoupling is done in different ways and how it is conducted determines its sustainability and emissions impact. Here on Earth, the element is derived either from water or fossil-fuels.
Currently, 70 million metric tons of H are produced globally every year. It is used in oil refining, ammonia production, steel manufacturing, chemical and fertilizer production, food processing, metallurgy, and more.
Most of this hydrogen is made through a process called steam methane reforming. A catalyst reacts with methane and high temperature steam which results in H, carbon monoxide and carbon dioxide. To produce more hydrogen, the carbon monoxide reacts with steam and a catalyst and also leaves CO2 as a by-product.
When this method uses fossil fuels, it is called gray hydrogen. Currently, this sector produces 830 million metric tons of CO2 emissions each year. Therefore, it is not considered sustainable.
When the CO2 emissions from the production of H are captured via CCS, then it is called blue hydrogen. This process cuts half of the amount of carbon otherwise produced, but it’s still not emission-free.
Another method for H production is through the electrolysis of water. Electrolysis employs an electric current to split water into H and oxygen in an electrolyzer. This process produces nothing but oxygen as a by-product.
If renewable electricity is used to power the electrolysis of water, it is considered clean and emissions free. The resultant hydrogen from this process is called green hydrogen.
What Is Hydrogen Used For?
H is an energy source, it can be used in gas or liquid form, be converted into electricity or fuel. It is applied as an industrial chemical and for transport, power and heating. H is highly flammable, light and contains almost three times as much energy as natural gas.
It has the NFPA 704’s highest rating of 4 on the flammability scale as it explodes when mixed even in small amounts with air. H is 57 times lighter than gasoline fumes and can quickly disperse into the atmosphere, which is one of the positive features.
H is also used with fuel cells to power anything that uses electricity. There are hydrogen fuel cell vehicles or cars that use it as fuel. The energy efficiency of a hydrogen fuel cell is two to three times higher than an internal combustion engine fueled by gas. H can also be used as a precursor for other energy carriers, from ammonia to synthetic hydrocarbons.
Challenges For Wide Adoption Of Hydrogen
Some of the major challenges that hinder hydrogen’s widespread use as an alternative low carbon fuel are flammability and lightness. Compared to gasoline, natural gas, and propane, H is more flammable in the air which increases the risk of accidents.
Because it is so light, it is difficult to be transported. It needs to be compressed 700 times atmospheric pressure so it can be delivered as a compressed gas. Alternatively, it needs to be cooled to -253˚C to be liquefied.
A challenge for fuel cell electric vehicles is how to store enough hydrogen in the vehicle to achieve the conventional driving range of 300 miles.
A lot of energy is also lost when using renewable electricity to produce green hydrogen. The electrolysis process results in an immediate 22% energy loss, and the transport, storage and distribution – a further 22% energy loss.
The distribution of pure hydrogen is also an issue. Natural gas pipelines can be used, however, H can make steel pipes and welds brittle, causing cracks. That means it should only be blended with natural gas to be safely transported. The distribution of pure hydrogen would require a completely separate infrastructure.
Cost
The most important scalability challenge in front of H, however, is cost. When used for heating, it costs four times as much as natural gas. As a way of transporting energy, hydrogen pipelines cost three times more than power lines. Currently, gray hydrogen costs about €1.50 per kilogram, blue – €2 to €3 kg, and green is €3.50 to €6 kg.
Green H is more expensive than the others because of the price of electrolysis. There is no mass manufacturing of electrolyzers anywhere in the world, therefore their cost remains high. The process of producing green H also requires very large amounts of cheap renewable electricity. That is still not the case in many parts of the world.
The scalability of the hydrogen fuel cell technology is also constrained by the high cost of platinum. It is used at the anode and cathode as a catalyst to split hydrogen. Researchers are trying to find more efficient and less costly materials and improve the performance of fuel cells.
Where Is The Hydrogen Market Headed?
Many experts estimate the market needs at least 10 years before a widespread green H adoption. The limits of the existing infrastructure could be reached fairly quickly. That means capacity needs to grow both pipeline infrastructure and transmission lines.
An increase of electrolyzers manufacturing needs to happen, however that depends on policy changes to support the markets along with infrastructure changes.
To a great extent, cutting the cost of electrolyzers will be critical to reducing the price of green hydrogen which would take time and scale. According to IEA, electrolyzer costs could fall by half by 2040, from around $840 per kilowatt of capacity today.
The biggest expectation is that as the technology improves, green hydrogen would achieve cost-parity with polluting grey hydrogen. The hope is it could do the same as solar energy where costs were cut five-fold over the past decade.
It is forecasted that low-carbon and renewable hydrogen production needs to meet 18% of global final energy demand by 2050 to be in line with the 2°C goal of atmospheric temperature increase. That means a ten-fold rise in the market compared to today.
According to a market report, the total global hydrogen generation market size – green, blue, and grey, was valued at $120.77 billion in 2020. It is expected to expand at a compound annual growth rate (CAGR) of 5.7% from 2021 to 2028. Goldman Sachs is more optimistic and gives green hydrogen a share of 25% to meet the world’s energy needs by 2050 and a market size of $10 trillion by 2050.
A McKinsey study says that by 2030, the US hydrogen economy alone could be a $140 billion market and support 700,000 jobs. According to the European Commission, a ten-fold projected increase by 2050 of the green hydrogen market would generate energy sales of €630 billion per year globally.
Adoption Around The World
The European Union is leading the world in clean hydrogen with more renewable projects planned than elsewhere. Iberdrola, a Spanish utility, for example, has scheduled to build the largest green hydrogen plant for industrial use in Europe worth €150 million.
China also has announced hydrogen projects, including solutions for transport, steel, and power generation. North America brings 19 projects, or less than 10% global share. In the US, the Biden administration is committed to making green hydrogen cheaper than grey hydrogen from shale gas. The US energy company SGH2 has planned to build the world’s biggest green hydrogen facility in Lancaster, California.
Bill Gates venture fund Breakthrough Energy is investing in the European Green Hydrogen Acceleration Center. The organization aims to develop green hydrogen technologies and bring the market to €100 billion a year by 2025. Breakthrough Energy has also invested in ZeroAvia, a company developing hydrogen-fueled zero-emissions aviation.
Conclusion
There are different ways to make low-carbon hydrogen. As production and distribution costs are coming down, the interest towards green hydrogen is expected to pick up and turn into a potential solution for the world’s rising energy needs. There are arguments for and against H use in heating, transport and heavy industry because of the challenges it provides, so addressing those and minimizing risks is also critical for its widespread adoption.
