From giant kites to foldable wings, here's what container ships could look like by 2050 as companies race to decarbonize their supply chains

Companies are racing to find a sustainable — and scalable — replacement for gas-guzzling container ships. Here's what they've come up with so far.

• Shipping giants are racing to find scalable green alternatives to gas-guzzling container ships.
• From rotor sails and giant kites to retractable wings, some firms are attempting to re-invent the sail. 
• Other shipping giants are betting big on green methanol fuel derived from agricultural waste.

With pressure from regulators to decarbonize international shipping, companies big and small are racing to identify green alternatives to the gas-guzzling container ships that account for an estimated 3% of global greenhouse emissions.

Many of the ideas floating around today leverage some form of high-tech sail, a futuristic take on the wind-powered voyages that have transported goods for as long as global trade has existed. 

Geir Fagerheim, SVP of Marine Operations at the Norwegian shipping company Wallenius Wilhelmsen, told Insider that a variety of factors need to be considered when designing a wind-powered cargo ship, including safety, functionality, crew comfort, and most importantly, speed. 

"There's big pressure on having the shortest possible transit times on the ocean," he said. "But obviously, when you're going to push the vessels very fast and drive down transit time, it also comes at a very high environmental cost in the form of fuel consumption and emissions."

In collaboration with several partners, Swedish shipping company Wallenius Marine developed "Oceanbird," a cargo ship powered by retractable wing-like sails that the company claims will be able to carry 7,000 cars and reduce emissions by 90%. 

Developing the tech behind any sustainable cargo ship is impressive in itself, Fagerheim said, as ocean-faring vessels must carry all the energy they need along with them, compared to say an electric vehicle that can stop on the road to charge up. Combined with the lack of emissions-free fuel, wind is positioned to be the industry's most accessible clean energy source. 

But the real challenge, Fagerheim said, is convincing clients to get onboard with the boat's slower transit time compared to a traditional container ship. No matter how innovative the tech itself is, he explained, it doesn't matter unless companies buy into the idea that a slightly slower delivery time is a worthy tradeoff.

Together, the two challenges make maritime shipping "the hardest industry to abate in terms of carbon emissions," Fagerheim told Insider. 

But as more shoppers prioritize sustainability, some big name brands are pledging to use sustainable cargo ships once the designs become a reality. 

In September, cosmetics giant Lush announced it would ship products on the first vessel built by Veer, a ship-builder aiming to have two 100% emissions-free container ships on the water by the end of 2024.

The start-up recently received an "approval in principal" from the American Bureau of Shipping, a classification that confirms the engineering behind untested technological concepts. Veer's cargo ship concept uses DynaRig sail technology and green hydrogen fuel cell engines to optimize transit times, and is designed to only carry lighter cargo. 

"Speed is a critical part of this design," Danielle Doggett, the founder and CEO of Veer, told Insider. "If we're committed to being completely zero emissions regardless, why not go fast? Why not create a performance sailing vessel?"

"I want to create the fastest container sailing ship that we can create," she added. 

Building entire new fleets of ships can get expensive. One company's solution is a parasail-like kite that automatically unfurls through a ship's front bridge window at the press of a button, towing the ship forward. 

The "Seawing" kite leads to a 20% decrease in gas emissions, according to Airseas. "K" Line, a Japanese shipping company, has signed a contract to purchase 50 of the automated kites over the next 20 years. Aircraft manufacturer Airbus has also placed an order, the company says, though how many is unclear. 

Maersk, one of the world's largest shipping companies, is betting that green methanol fuel is the key to reaching its net-zero emissions target by 2050. 

In October, the shipping giant ordered an additional six container vessels with dual-fuel engines able to operate on the sustainable fuel, bringing the total number to 19. The problem with methanol is that there isn't enough of the fuel to even account for 1% of the industry's yearly fuel consumption, as Grist reported last year. 

Palle Laursen, Chief Fleet & Technical Officer at Maersk, said green methanol is the best scalable sustainable fuel solution of the decade and that investing in its production "adds further momentum to the rapid scaling of availability needed to bring down the premium on the gas."

Correction: November 28, 2022 — An earlier version of this story misstated that Oceanbird was developed by Wallenius Wilhelmsen, a Norwegian shipping company that has committed to ordering the first vessels from the Oceanbird concept. Oceanbird was developed by the Swedish shipping company Wallenius Marine.