Shipping companies are revisiting wind power to reduce emissions and fuel consumption, driven by stricter environmental regulations. In 2018, Maersk installed two 30-meter-high rotor sails on its tanker, the Maersk Pelican, but an analysis found it only led to an 8% drop in fuel consumption. Environmentalists argue that regulations from the UN's International Maritime Organisation (IMO) are too weak to drive significant change, despite a pledge to halve shipping emissions by 2050. Many new ships being built currently do not include wind propulsion systems.
Despite the slow adoption, wind power advocates are hopeful that new regulations, like the IMO’s Carbon Intensity Indicator, will spur wider investment. Erik Grundt, an analyst at Rystad Energy, predicts an "explosion in rotor sail adoption," noting that wind is "free" and sails are "proven technologies" compared to the cost and toxicity concerns of clean fuels like hydrogen and ammonia. However, industry observers point to uncertainty about the actual fuel and energy savings on large vessels, some carrying over 100,000 tons of cargo, as a major factor holding back investment. Tristan Smith, a shipping researcher at UCL, highlighted that an 8% reduction doesn't significantly contribute to a 50% overall emission reduction.
Costs are also a significant barrier; Cargill's Dieleman stated that the cost of installing wind propulsion systems is holding companies back, and it could take seven years to recoup the investment. He added that widespread use across Cargill's fleet is not economically sensible at this stage and that a significant number of wind-powered ships are unlikely before 2026 or 2027 due to lead times in the industry. The reset of global supply chains and changing trade routes also add to the uncertainty regarding the long-term benefits of wind propulsion for specific routes. Environmentalists criticize the CII regulations for potential loopholes that allow companies to appear more carbon-efficient without making meaningful changes.
In a more recent development, Maersk Tankers has taken a significant step by installing four 24-meter bound4blue eSAIL suction sails on the MR tanker Maersk Trieste. This is the first of 20 units to be installed across five MR vessels under a contract signed in December 2024. These eSAILs are designed to generate lift up to seven times greater than conventional rigid sails and are expected to deliver double-digit percentage reductions in fuel use and CO2 emissions, improving the vessel's Carbon Intensity Indicator (CII) rating. The installation process was designed for minimal downtime, using a two-step retrofit workflow across China and Belgium.
This move by Maersk Tankers, following a previous less successful trial, signals a growing intent towards repeatable rollout of efficiency technologies. Other shipowners like Louis Dreyfus Company, Eastern Pacific Shipping, Odfjell, Klaveness Combination Carriers, and BW Epic Kosan are also adopting eSAIL technology, indicating that wind propulsion is transitioning from a niche innovation to a mainstream decarbonization strategy due to tightening regulations, rising fuel costs, and increasing industry confidence.
