April 28, 2022 • 3 min read
What role will hydrogen play in future energy systems?
For decades, hydrogen has promised a pathway to reduce the world’s reliance on fossil fuels and cut CO2 emissions, and our customers are closer than ever to realizing its clean energy potential.
Hydrogen is the simplest element in the universe. However, extracting, transporting, and storing it sustainably is a complex process.
Hydrogen is an energy carrier suited to many industrial applications. The by-product of burning hydrogen is water, rather than carbon dioxide. That means it can be a key contributor to a low carbon energy system.
So why aren’t we using this clean energy everywhere?
Current hydrogen production methods emit a lot of carbon dioxide into the atmosphere. But these carbon-intensive processes are not the only option to produce it. Emerging hydrogen technologies could free many industries from carbon-intensive energy forever.
The uses of hydrogen today and tomorrow
Global demand for hydrogen has grown by over 300 percent since 1975, according to the IEA. That’s because hydrogen is a key input in oil refining, fertilizer production, ammonia production, and other chemical manufacturing processes today.
Low carbon hydrogen can power vehicles ranging from hydrogen fuel cell cars to heavy trucks to trains. It can also be used as a feedstock to product synthetic fuels and e-methanol for the aviation and shipping sector in so-called power-to-x projects. This is critical because the transportation sector currently accounts for up to 24 percent of global CO2 emissions from fuel combustion (IEA).
Clean hydrogen also has a growing role in displacing carbon intensive steelmaking processes and other high-temperature industrial processes that aren’t suited to green electricity alone.
Hydrogen and ammonia can also generate power in traditional gas and coal fired power stations to make use of existing electricity infrastructure and to store energy from excess renewable electricity off-peak.
What are the different colors of hydrogen?
It’s rare to find a pure hydrogen molecule in nature. But hydrogen exists within many other elements. There are many ways to extract it, and we use colors to distinguish how hydrogen is made.
Grey hydrogen represents over 95 percent of the production of hydrogen today. Producers extract this hydrogen from natural gas through a process called steam methane reforming (SMR). This releases the carbon dioxide by-product into the atmosphere.
Blue hydrogen producers use natural gas and steam methane reforming, but the carbon dioxide by-product is trapped and injected underground through carbon capture and storage (CCUS). This results in lower carbon emissions than grey hydrogen.
Green hydrogen is an even lower carbon approach, with no reliance on fossil fuels. But how do you produce green hydrogen?
Green hydrogen involves renewable energy and a process called electrolysis. This process uses a device called an electrolyzer, which sends renewable electricity through water to separate the hydrogen atoms from oxygen.
Producing green hydrogen energy doesn’t emit any carbon dioxide into the atmosphere, so long as the electricity for this process comes from a renewable energy source.
Pink hydrogen comes from electricity sourced from a nuclear reactor, rather than solar or wind power. Like green hydrogen, the process for extracting pink hydrogen involves splitting hydrogen and oxygen through the electrolysis of water. And because nuclear power is a low-carbon energy source, pink hydrogen is low carbon, too.
Turquoise hydrogen is made using a process called methane pyrolysis to produce hydrogen and solid carbon. In the future, it may be valued as a low-carbon emission hydrogen if the thermal process is powered with renewable energy and the carbon is permanently stored or used. It’s a new entry to the hydrogen scale, and production has yet to be proven at scale.
Each approach has different uses, but at present, only blue hydrogen, green hydrogen, and pink hydrogen will enable decarbonization. If proven at scale, turquoise hydrogen has potential for future decarbonization enablement, too.
The role of hydrogen in a low-carbon economy
Low-carbon hydrogen is key to our future energy systems. It can tackle the most carbon-intensive processes in the energy, chemicals, and resources sectors, as well as heavy industry and transport. These industries will depend on green hydrogen to operate sustainably in the future.
But to get there, we’re going to need a lot of it. The volume of low-carbon hydrogen produced today is only a fraction of the scale the world needs to meet future decarbonization commitments.
And yet, this proposition becomes more viable every day. There is a clear pathway to scale up low carbon hydrogen production all over the world. And with so many industries set to benefit from clean hydrogen, the greatest benefits await the bold businesses that invest in its potential today.