Hydrogen-powered ship could transform shipping industry, helping cut greenhouse gases

The shipping industry currently emits 3% of all greenhouse gases. To keep temperatures within safe limits, experts say, ships and other vessels will have to be decarbonized. Could green hydrogen be the answer?

On a river in the northern sector of Belgium, a vessel that is powered by a fuel that everyone hopes will be the secret to help reduce greenhouse gases generated by ships in all regions of the planet in the future, hydrogen.

The fuel was tested on the Hydroville, a special 16-passenger ferry that runs between Kruibeke and Antwerp. Hydroville was launched three years ago as the world's first hydrogen-powered passenger ship. Its hybrid engine allows it to run on both hydrogen and diesel.

“We decided for ourselves, look, we have to start with this today, although there is no demand yet”, says Roy Campe, managing director of CMB.Tech, the R&D branch of CMB, which owns Hydroville. “We need to start today to make sure that in 10 years we can already start producing all of our low-emission ships. It's not a light switch that you just flip. ”

CMB is already in the process of building several more hydrogen-powered boats, including a larger 80-person ferry in Japan, due for launch in early 2021.

The small vessel sector is a great “laboratory” for expanding cleantech solutions to large merchant ships, according to Diane Gilpin, founder of the Smart Green Shipping Alliance. Currently, ships emit 3% of all greenhouse gases and emissions are expected to grow by up to 50% by 2050 if the industry continues on a normal path. Governments have pledged to cut emissions from shipping by half by 2050, but the industry has so far been slow to implement these measures.

It takes a lot of energy to move a ship across water, and that number tends to increase as world trade grows. To cut emissions, some of that energy could be reduced by using ships using more efficient designs, installing technologies to harness the wind, going a little slower to save fuel, or simply carrying less stuff.

But ultimately, if shipping is going to fully decarbonize – and it will have to if the world is to stay within safe temperature limits – it needs to find a way. substitute for fossil fuels.

CMB's hydrogen program is one of several transportation projects around the world testing how hydrogen and other fuels made from it, such as ammonia and methanol, can be used to power a low-carbon marine industry of the future. These fuels, together often referred to as “synthetic” fuels, are seen as a particularly promising option because they can be produced using clean electricity – like electricity. solar or wind energy – and burned without emitting greenhouse gases.

Why hydrogen?

Hydrogen isn't the only alternative fuel option, of course. Biofuels – fuels made from plant materials or animal waste – are another. But they have a wide range of planned uses in other sectors, while their sustainable production is limited, says Tristan Smith, a marine emissions researcher at University College London.

Batteries charged with renewable electricity are another option. But there will likely be limits on how far they can carry; large ships crossing oceans would simply need too many batteries to run on them alone.

Nearly all hydrogen is produced using fossil fuels – in fact, 6% of global natural gas and 2% of coal currently goes into hydrogen production

Which leaves hydrogen and other synthetic fuels made from clean electricity. The gas is already widely used in industrial processes around the world – demand for it has increased threefold since 1975. But almost all hydrogen, which is already heavily used in industry, is produced using fossil fuels. In fact, 6% of global natural gas and 2% of coal currently goes into hydrogen production. While this type of hydrogen can be used to power ships with zero emissions from the ship itself, it is obviously not low carbon as fossil fuels are used to produce it.

But hydrogen can also be produced no fossil fuels, using renewable energy to split water in a process called electrolysis. This process is expensive and currently only 0,1% of hydrogen is made with it, but this is where the main hope for an environmentally friendly shipping fuel lies. “Green hydrogen can be truly emission-free over a full lifecycle,” says Marie Hubatova, an expert on transport emissions at the Environmental Defense Fund. “That means from the point where the fuel is extracted, or produced, to the point of combustion.”

The problem is that right now the availability of green hydrogen is simply not there, says Xiaoli Mao, a marine team researcher at the International Council on Clean Transport (ICCT). “Fuel producers need to see some legitimate demand to invest in their production, so it's like a chicken/egg problem – whether the ship technology develops first or the fuel side develops first,” she says.

CMB itself is already acting as a pioneer, building its own marine fueling station for hydrogen cars, buses and ships in the port of Antwerp, which will produce its own hydrogen using an electrolyser. “First we need to show, look, we are customers and we are willing to pay this amount for hydrogen,” says Campe. “And then you see, 'Oh, there's a business case for electrolysers'.”

How it will work on ships

Once hydrogen is produced, there are several ways to use it to power ships.

It can be burned in an internal combustion engine, as Hydroville is currently doing. One downside to this is that burning anything in the air that consists largely of nitrogen inevitably produces some level of nitrogen oxides – which are the main air pollutants.

These emissions could be tackled by installing some kind of after-treatment device, says Mao. But hydrogen can also be used in a fuel cell – a device that chemically converts fuel into electricity without the need to burn it, and the only emission is water. “The main challenges of doing this work on a ship are just making it big enough,” says Smith, noting the enormous expense of installing enough fuel cells to power a ship. “There is a real question whether or not this is an option that will work at scale on ships.”

Other options may exist for hydrogen. A UK company, Steamology, is in the early stages of developing steam-powered hydrogen electricity. Here, steam created by burning hydrogen with pure oxygen from a tank is used to drive a turbine, generating electricity. The technology is being tested on trains, but has great potential for use in the shipping industry, say its founders. “It's pretty rudimentary in many ways,” says Matt Candy, CEO of Steamology. “So we believe we have a steam electric solution. We have no nitrogen oxides, our emission is genuinely zero. But we have to go through the problem of burning hydrogen in an oxygen environment. ”

Despite these promising technologies, the switch to hydrogen fuel is not without major challenges.

For starters, it's highly flammable. The CMB runs training programs for its crew and others, examining everything from maintaining a hydrogen system on board a ship to dealing with fire safety. It is also very expensive, although its costs are coming down, it will require extra electricity capacity.

But the real challenge with using it for long-distance shipping is how difficult it is to store it. Hydrogen cannot simply replace supply fuel in the current system. To store it on board a ship as a liquid, it needs to be frozen at cryogenic temperatures of -253C (-423F), says Hubatova. And yet, it takes up a lot of space – about eight times more than the amount of gas and marine oil needed to provide the same amount of power, according to EDF's analysis.

The extra space needed for hydrogen has caused concern in the industry that it may be necessary to clear the cargo to make room for the fuel. But an ICCT analysis concluded that this barrier could be overcome. He found that 43% of current trips between China and the United States – one of the busiest shipping lanes in the world – could be made using hydrogen without the need for cargo space or to stop more often to refuel. Almost all trips could be powered by hydrogen, with only minor changes in fuel capacity or operations, he concluded.

Using hydrogen to produce ammonia can be an alternative

Hydrogen is often used as an umbrella term for synthetic fuels, but many experts believe another option is actually better: using green hydrogen to make green ammonia, another fuel that can be burned or used in a fuel cell. Ammonia is much easier to store than hydrogen (it needs refrigeration but not cryogenic temperatures) and takes up about half the space because it is so much denser. It can also be converted back into hydrogen onboard a ship, meaning it can be loaded and stored on the ship like ammonia, but used in a hydrogen fuel cell.

“Right now, the best bet is just turning [hydrogen] into ammonia,” says Smith. “Ammonia is much cheaper to store; you can store it in a pressurized tank, so you don't need to have any kind of cryogenics. It's just a tiny amount more expensive to make than hydrogen. ”

The caveats? First, ammonia is toxic to both humans and aquatic life, so care is needed. Second, the extra step to convert hydrogen to ammonia will use more renewable electricity, making ammonia slightly more expensive.

Still, ammonia is seen by many in the industry as the most viable option: a consortium of companies recently received EU funding to install the world's first ammonia-powered fuel cell on a ship in 2023.

Green hydrogen itself is expensive, and for a long time many doubted whether it would ever be cheap enough to be widely used as a fuel. But huge cost reductions in wind and solar energy in recent years have helped to challenge that view, with some experts projecting that the cost of green hydrogen will drop significantly further over the next decade.

change needed

After a lethargic start to climate action over the past few decades, there are some signs that the shipping industry is starting to pay off. attention to the risks posed by the climate crisis. According to Smith, large percentages of the industry now think they will need to move away from fossil fuels, with hydrogen derivatives such as ammonia considered the most likely alternatives. “There are a million questions about how we got from where we are today to that ultimate goal,” he says. “But the idea that this is where we are going now is very, very, very popular.”

This is supported by groups such as the Getting to Zero Coalition, a group of shipowners, ports and countries that have committed to introducing zero-emission ships to deep sea lanes by 2030. Earlier this year, the group compiled a list of 66 zero-emission pilots and demonstration projects for worldwide shipments, many involving hydrogen fuels. “They are likely to be the group that are really pioneering hydrogen and ammonia ships on a larger scale than the pilots,” says Hubatova. “This bottom-up action is very important as it sends the right signal to the industry at large.”

But in the absence of stronger regulation of shipbuilding emissions, the speed of decarbonization will be limited. “The role of the top-down approach in the form of regulations is also crucial, as it will ensure that everyone goes carbon-zero, not just the most progressive players,” says Hubatova.

We have options: we can essentially phase out fossil fuels on ships, or we can try to encourage the market for hydrogen-derived fuels.

Tristan Smith

Indeed, Smith argues that the main constraint to emissions from shipping comes not from technological barriers but from the political process – most significantly, the International Maritime Organization, the UN body responsible for dealing with the climate impact of shipping. “We have options: we can essentially phase out fossil fuels on ships, or we can try to encourage the market for hydrogen-derived fuels,” he says.

Smith himself envisions three stages over the next 15 years for hydrogen-derived fuels in shipping: an increase in testing and first-of-its-kind from now to 2025; an uptake of hydrogen by industry firsts by 2030; then a broader scale will be implemented after 2030 as costs come down and infrastructure for resupply becomes more widespread. Shipping companies are already talking about ordering “zero-ready” ships that can be easily retrofitted for ammonia, he adds. “Their mentality is, I know in 10 years I'm going to have to do something to run that ship with ammonia,” he says.

The outcome of shipping emissions depends on a wide range of factors, from regulations to the adoption of other technologies. But there is a growing body of evidence on how quickly the shipping industry can decarbonize if it decides to, with one major report finding that it could almost completely decarbonize by 2035 using currently known technologies, including alternative green fuels like hydrogen.

Gilpin believes the industry could halve emissions by 2030. “If we treated this climate emergency like we treated the Covid emergency, we certainly could,” she says. “But we didn't, we thought 'Oh, it's a little difficult, let's have another meeting about it.'”

Mao agrees that to ensure widespread adoption of lower-emissions transport technology, strict mandatory regulations are vital. Even if hydrogen fuels won't be widely used for a decade or more, she says, "we really need to start now."

“There are a lot of barriers, let's face it,” she says. “We must dedicate our research money to making this a reality in the future.”