What’s The Deal With (Green) Hydrogen?
Lately there’s been a lot of buzz about hydrogen. What’s the hype? Many people think that green hydrogen will be a key player in the energy industry in coming years. When consumed in a fuel cell, the only byproduct is water — no nasty gases like carbon dioxide or methane. Further, it can be produced from numerous domestic sources like solar. Not to mention, hydrogen is the most abundant element in the universe. One could argue that this is the perfect option for a zero-carbon future.
Hydrogen in Colourful Terms
A quick google search about hydrogen will send you down a very colourful spiral. The type of hydrogen with the most focus today is called green hydrogen, also called renewable hydrogen. Hydrogen for heat is actually not new — but green hydrogen is.
The United States produces hydrogen from a process called steam methane reforming, where methane reacts with steam to create hydrogen and simultaneous by-products of carbon monoxide and carbon dioxide. This method is usually associated with gray hydrogen. If hydrogen is made from the gasification of coal and lignite it is classified as brown. Therefore, hydrogen is not an inherently sustainable fuel source. It’s the way we go about producing hydrogen that makes or breaks the level of emissions and carbon neutrality.
It is theoretically possible to capture the methane from gray or brown hydrogen, making it arguably more sustainable. This hydrogen is referred to as blue hydrogen, but it’s still very far from being sustainable as the carbon produced is only halved. Aside from this, there’s also pink hydrogen which is made from nuclear-powered electrolysis.
Natural Gas Reforming
In simple terms, for hydrogen to be produced, it must be separated from the other elements in the occurring molecules. The two most common methods are thermal processes like natural gas reforming and electrolysis.
Hydrogen production usually involves steam reformation, making up about 95% of commercial hydrogen today. Natural gas is the primary methane source for hydrogen production by petroleum refineries and industrial facilities. Following natural gas as other potential methane sources are biofuels and petroleum fuels.
Steam reforming is a process that requires high temperatures for steam to react with hydrocarbon fuel. Hydrocarbon fuels are often reformed to produce other substances as well, like renewable liquid fuels and gasified coal or biomass. This method works by separating the hydrogen and carbon atoms in methane, where hot steam reacts with methane in the presence of a catalyst.
Electrolysis is the way most people are trying to approach green hydrogen as this is a sustainable method that does not release toxic gases. Hydrogen fuel cells run an electrochemical process that combines hydrogen and oxygen to create electricity and water. When you reverse this, we have — you guessed it — electrolysis. Such a process occurs in an electrolyzer, which functions like a fuel cell in reverse. Where a fuel cell uses the energy of hydrogen molecules, an electrolyzer produces hydrogen from water molecules. Renewable energy sources like wind and solar can provide the needed electrical current.
This sounds pretty ideal, but if it is, then why does it only account for 5% of global hydrogen production? As is the case for many new technologies, electrolysis is quite a high-cost option. We will need more efficient and cost-effective electrolyzers and scaleable power generation capacity, and as this begins to happen, the cost of production will decline.
More on the price — if we compare the cost for hydrogen fuel with something like gasoline, there’s a big difference. Nearly 4 kilograms of gasoline have around the same energy as 1 kilogram of hydrogen. The cost of green hydrogen is at $3 to $7.50 per kilo, compared to $0.90 to $3.20 for production using steam methane reformation. A hydrogen-powered vehicle is three to four times the cost of gas-powered alternatives.
There are other concerns with hydrogen as a whole, as well, a big one being safety. Hydrogen is flammable so if it were to be used for refuelling stations there could be risks if there were a link. However, it’s important to keep in mind that the industrial sector has been transporting hydrogen for years now and nothing very severe has happened. On top of this, there are other flammable substances like gasoline that we use day-to-day.
Elon Musk’s View on Hydrogen
One huge opposer to hydrogen is Elon Musk, the CEO and co-founder of Tesla. Where lots of competitors have begun to look into hydrogen fuel cells for vehicles (more on this in the next section), Tesla has dismissed this quickly. Musk says that hydrogen fuel cells are “mind-bogglingly stupid”, “staggeringly dumb”, and “a load of rubbish”. The main reasons he says this is because of the high cost and low efficiency.
While hydrogen has a high energy mass, it has such low density that the pressure needed to store it contributes to enormous complexity, especially when adding the difficulty of the technology itself. The hydrogen has to be stored as a gas, not a liquid, and this would require a high-pressure fuel tank. The components will need to allow compact and lightweight hydrogen storage systems, and life-cycle energy efficiency improved.
More About Hydrogen-Powered Vehicles
Having a hydrogen fuel cell vehicle in theory sounds great, where we would be able to use a lightweight electrochemical system instead of a grid-charged battery pack. This would work by removing the electrons from hydrogen through a catalyst reacting with pressurized gas in tanks. This hydrogen can then power a vehicle, and when the job is complete, the electrons can go back to the fuel cell and meet oxygen to create a by-product of water which is released through the car’s tailpipe.
This could be beneficial because the vehicle would run in silence, be provided with plenty of acceleration, not require an electric plug, and use hydrogen as a replacement for gasoline. The charge time for a fuel cell is also pretty fast, taking 6x less the amount of time to charge. Excess electricity is stored in a lithium-ion battery when the vehicle needs to accelerate. Again, though, fuel cells need to be worked on for efficiency because they don’t produce many electrons.
Many car companies (not including Tesla) are creating a market for hydrogen fuel cell cars. Toyota and Honda have both made commitments to hydrogen and are beginning to open fueling stations.
If you want to learn more, here are some pretty cool startups in the hydrogen field.
- HyPoint — working on turbo air-cooled fuel cells for aviation and air mobility applications like air taxis and logistic drones.
2. EnerVenue — makes metal-hydrogen batteries for energy storage applications that can withstand extreme temperatures.
3. ZeroAvia — enables zero-emission air travel at scale for half of today’s cost.
4. Ways2H — uses a thermochemical process to convert waste biomass into renewable hydrogen fuel.
5. H2GO Power — developing AI management and optimization algorithms to produce and store clean hydrogen.
Although there are certainly limitations, hydrogen could serve as an environmentally friendly alternative to fossil fuels. It has lately been attracting the attention of numerous investors, companies, and individuals — and this is fitting because having the ability to use an energy source that produces only hydrogen and oxygen with no negative impact could be extraordinary. One day hydrogen could be powering your ride to work, and luckily we have emerging innovations paving the way to this reality.