As customers look to clean up their supply chains in the near term, ships that generate lower emissions are going to be in demand. New regulations have come into effect this year, with more on the horizon, that put further pressure on shipowners to do whatever possible to reduce their emissions.

As of January 2023, each ship’s specific emissions are measured and assessed according to International Maritime Organization (IMO) regulations, and industry stakeholders have no choice but to become aware of the emissions generated by each commercial ship. This was a significant first step into an era of emissions thresholds, carbon taxes and emissions related restriction.

Many current milestone targets for maritime decarbonization are decades into the future, causing the industry to focus on big picture concepts such as new fuels, new infrastructure, new engines, and new technology. But the energy transition is already underway and ships have a relatively long service life, typically 25 years. Modifications and retrofits to existing vessels have become a necessary consideration for the fleet’s younger ships that are expected to operate into the 2030s and 2040s.

There are innovative ‘bolt on’ emissions reduction solutions currently available to shipowners, with additional technologies nearing the point of commercialization.

Rotor Sails

Flettner rotors, more commonly known as rotor sails, are large rotating cylinders installed on ships that provide propulsion through an aerodynamic principal known as the Magnus effect. Modern rotor sails provide auxiliary propulsion to lighten the load on a ship’s engines thereby reducing emissions. The technology has a long history of being used to propel ships – the first rotor sail was tested in the early 20th century.

It may seem farfetched that a rotating cylinder fixed to a ship carrying hundreds of thousands of tons of cargo can make a difference, but the fuel savings have been reported to be as high as 8.2%. The reduction translates into significant cost savings over time considering the amount of fuel ships burn, so much so that Brazilian mining giant Vale has announced that they are considering employing the technology on 40% of the ships they use to move iron ore.

Air Lubrication

Silverstream, a British engineering firm that specializes in innovative solutions for the maritime sector, has pioneered air lubrication technology for ships. Their systems pump air beneath the hull as it moves through the water. The air ‘carpet’ that forms underneath the waterline decreases frictional resistance and translates into a reduction in fuel consumption and associated emissions.

Silverstream has been perfecting its systems for over a decade, and the fuel savings can range from 5-11% depending on the type and size of ship. One of Silverstream’s air lubrication systems was recently installed on the MSC Irina, which along with its sistership is the largest containership in the world. The Company is targeting 500 installations by 2025 and up to 4,000 installations by 2032. The Financial Times named Silverstream the fourth fastest growing European company on its 2023 FT1000 list.

Onboard Carbon Capture and Storage (CCS)

Beginning in 2020, the IMO mandated that ships operating in international waters reduce sulfur emissions by 80%. This could be achieved in one of two ways – a system known as a ‘scrubber’ is installed to remove sulfur particulates from exhaust or more expensive low-sulfur fuel is used. Many shipowners have chosen to install scrubber systems aboard their ships, and an entire industry emerged around these exhaust cleaning devices.

A concept known as onboard carbon capture and storage (CCS) intends to build on the scrubber concept by removing CO2 from a ship’s exhaust. The technology to remove the CO2 exists, but creating a system that can cost effectively capture and store carbon within the confines of a ship is difficult. Several industrial technology manufacturers and shipowners have invested time and money to make the systems viable, but few commercial examples exist. One of the major hurdles to implementing onboard CCS is storing the massive amounts of carbon that is collected. It is possible for 22-92,000 tons of carbon to be collected annually from a midsized tanker or large containership, respectively.

Wartsila, a Finnish engineering firm that has played an integral role in making maritime decarbonization concepts a reality, announced that they have taken their first order for a scrubber system that includes carbon capture technology. The company has begun piloting onboard CCS systems that could collect 70% of CO2 emissions, and the recent order for four commercial systems that will be compatible with the piloted technology is an important milestone for proving the commercial viability of onboard CCS.
Source: Article from Hal Malone, Sea/Switch Partners Principal and Partner in the BSEA ETF