Back to the Future

The race to decarbonize global shipping is in full stride with a multitude of proposed solutions. They’re today’s answer to “putting wind back in the sails.”

Many leading shipping companies are planning to gradually transition to zero-carbon vessels, like Maersk's future methanol-fueled containership series (Maersk file image)

Published Mar 18, 2022 11:43 PM by Mia Bennett

(Article originally published in Jan/Feb 2022 edition.)

In 1838, with black smoke belching out of its single funnel, the steamship SS Sirius sailed into New York Harbor, having left Ireland 18 days prior. The wood-hulled vessel was the first transatlantic voyage to be powered entirely by coal. Sirius’ voyage opened a new, fossil-fueled era for shipping, foregoing gusts of wind for clouds of soot.

Today, vessels burn petroleum instead of coal. But they’re still powered by fossil fuel, generating carbon dioxide (CO2) emissions amounting to two-to-three percent of the world’s total. Recognizing in the late 1990s the global shipping fleet’s responsibility for climate change, the International Maritime Organization (IMO) began tackling greenhouse gas (GHG) emissions.

CO2 emissions attracted scrutiny due to their ability to exacerbate the greenhouse effect and propensity to linger in the atmosphere for decades, if not centuries, and the IMO in 2018 published its initial strategy on reducing ships’ GHG emissions. It called for lowering CO2 emissions across international shipping by at least 40 percent by 2030 and 50 percent by 2050 compared to 2008 levels.

A Multitude of Options

To achieve these lofty goals, shipowners are exploring a multitude of options. Dr. Martin Koller, Global Product Manager & Head of Laboratory (Air Pollution Control and Marine Solutions) at ANDRITZ in Austria, ran through the pros and cons of three different decarbonization options.

The first, batteries and fuel cells, is an “interesting” technology, according to Koller, “but only feasible for short routes and small ships like smaller ferries.”

The second is “fuels of the future,” like methanol or ammonia. Yet these two options have lower energy density than conventional fuels and safety issues like flash points and hazardous chemicals.

The third option is carbon capture and storage (CCS). Koller observes, “The largest problem is the storage of CO2 onboard. Every ton of burned fuel produces three tons of CO2, meaning the longer the ship is sailing the higher the load. The goal should be to capture CO2 only at a removal rate of 30 to 50 percent to minimize the storage problem.”

While this capture rate appears sufficient to meet the IMO’s GHG strategy, CCS remains unmentioned as a technological option. “Hopefully, this will change in the near future,” Koller says. In at least two of these three decarbonization strategies, ANDRITZ, which oversees projects from CO2 capture to biomass plants and hydropower, is making significant advances. The company recently started up the world’s first fossil-free biomethanol plant at a pulp mill in southern Sweden. With the help of ANDRITZ’s self-developed A-Recovery+ concept, the plant produces 5,000 tons a year of green biomethanol from the pulp-making process, which can be used as a virtually carbon-free marine fuel.

Another company making strides in alternative fuels is TECO 2030. Tore Enger, Group CEO, says, “TECO 2030 firmly believes that by bridging the gap between fossil fuels and alternative fuels, we can reach the stringent goals of the IMO to cut GHG emissions from shipping by 50 percent in 2050.” In pursuit of zero-emission shipping, the Oslo-headquartered company is researching hydrogen fuel cells, onboard CCS and exhaust gas cleaning systems.

Hydrogen fuel cells are one area of excitement, especially in Europe, where the E.U. is pushing the technology to help lower the continent’s emissions. “Fuel cells have a longer range, weigh less and take up less space than large batteries,” Enger notes. “They’re just as mobile and flexible as traditional diesel generators and produce much less noise.”

Future Fuels

The nearly 200-year old Finnish company Wärtsilä is also focused on improving efficiency and developing future fuels. Aaron Bresnahan, President & Managing Director of Wärtsilä North America, identified a clear series of steps to decarbonization for shipowners.

“First, benchmark the performance of your fleet and vessel to set relevant targets based on regulations or your own level of ambition,” he explains. “Then, select solutions that help you meet those targets or enable you to retrofit to meet them later on. Finally, work with a trusted partner to de-risk your decarbonization, supporting you in achieving your desired outcomes across your vessel’s lifecycle.”

For ships looking for a long-term partner to help them navigate a period of rapid transition, Wärtsilä offers both the market and regulatory know-how and cutting-edge technology to achieve decarbonization.

Its advances in future fuels have been particularly rapid. “In March last year, we began testing combustion of ammonia in our research laboratories,” says Bresnahan. “By the end of the year, we were running a full-scale engine on a blend of 70 percent ammonia.” Over the past seven years, the company has also invested heavily in methanol, having first carried out a retrofit installation on the ro-pax ferry Stena Germanica in 2015. Soon, five methanol-capable Wärtsilä 32 engines will power a Van Oord windfarm installation vessel due to come into service in 2023.

Future fuels are just one of numerous pathways to decarbonization that Wärtsilä is exploring. As part of a joint project with RINA and other partners, the company is seeking to “marinize” a system that can convert LNG into hydrogen onboard.

Despite these successes, Wärtsilä isn’t putting all its eggs in the future fuels basket. In December, the company installed the Wärtsilä HY module, comprising batteries and an energy management system, on one of the world’s most advanced bulk carriers, the 60,000 dwt Paolo Topic. Ultimately, however, Bresnahan says, “The greatest challenges to decarbonizing ships will not be on the ship, but landside.” 

Landside Challenges

One Norwegian company, PSW Power & Automation Solutions, is working hard to overcome these landside challenges while simultaneously addressing issues at sea.

General Manager Eirik Sørenson describes how the company is responding to the ongoing electrification of Norway’s ports: “The greatest challenge will be to provide enough clean energy. Cutting emissions by electrifying platforms will be an additional burden for an already overloaded power grid.” He adds that any increase in power consumption from the offshore industry could result in power shortages and the failure to realize land-based industrial projects.

To prevent these problems, PSW is developing solutions for power production that combine shore power and hydrogen. It’s also looking to the sun for help with decarbonization. Solar cells connected to shore power systems can be installed on the roofs of large port buildings with the resulting energy directly transmitted to the vessel with limited power loss.

Vancouver-based Shift Clean Energy offers swappable batteries to deliver electricity when and where customers need it. CEO Brent Perry says that the company’s PwrSwäp service “can electrify ports, terminals, inland sea/short sea shipping vessels, other industrial sites and even isolated communities,” helping them switch from diesel to electricity.

He disputes the notion that energy storage systems (ESS) and electrification are unable to play a role in decarbonizing blue-water shipping: “Nothing could be further from the truth.” ESS solutions like PwrSwäp are useful for vessels transporting frozen food, like seafood, as it can help run high-power needs like refrigeration. For ships that might have significant accommodation needs, like cruise ships or those with large crews, ESS can supply electricity directly to meet those demands. This solution eliminates the need to burn carbon-intensive bunkering fuel merely to keep the lights on.

One innovative aspect of PwrSwäp is that it offers energy as a pay-as-you-go service, passing along significant savings downstream. “Customers pay a baseline subscription service fee, and then pay for electricity on a pay-as-you-go, per kilowatt hour basis,” Perry explains.

Capitalizing on high interest in PwrSwäp – especially to support inland shipping in Europe, Asia, and North America – the company is building charging stations along waterways. “Barge owners can simply stop and swap out new charged batteries as they move through,” he says. Offshore U.K. wind farms represent another example of industries rapidly adopting PwrSwäp to both electrify and reduce emissions.

Ships that want to decarbonize using technologies installed onboard can turn to CR Ocean Engineering LLC, a leading supplier of exhaust gas cleaning systems (scrubbers). Reflecting on some of the biggest obstacles to decarbonization, Nick Confuorto, former President & COO and now Senior Advisor at CR Ocean, says, “The biggest challenge is the very limited space onboard a ship as well as the shipowner’s desire to maximize revenue on each voyage.”

Ironically, the space limitation issue is almost the reverse of the problem faced by nineteenth century steamships, whose journeys were constrained by the amount of coal they could carry. 

While CCS is not generally seen as a viable solution for decarbonizing global shipping, CR Ocean sees major potential in the technology and is working closely with a Canadian partner to commercialize their CO2 capture and storage solution. “The technology is in an advanced stage of testing and will soon be ready for commercialization,” Confuorto says.


Sometime this year – close to two centuries after Sirius belched its way across the Atlantic in the inaugural coal-powered crossing – the world may welcome the first truly carbon-neutral container ship. Certain shipping lines have already laid claim to this title, but they’ve typically fudged it by combining biofuels with carbon offsets.

In Norway, where companies like TECO 2030 and PSW Power & Automation Solutions are just a few of the dozens of firms racing to decarbonize shipping, Yara International is building what it calls the first fully electric, autonomous container ship. If MV Yara Birkeland lives up to its promise, the vessel will go a long way toward making the IMO’s ambitious decarbonization targets seem a little more within reach. – MarEx

Dr. Mia Bennett teaches at the University of Washington and is a frequent contributor to The Maritime Executive.

The opinions expressed herein are the author's and not necessarily those of The Maritime Executive.