DNV: Significant decarbonization of existing fleets is achievable

A project involving COSCO Shipping, CHI Shanghai, MARIC, suppliers, and DNV demonstrated how complex retrofits of vessels to methanol can be practically achieved, according to a recent article from DNV.

As explained by Jan-Olaf Probst, Executive Vice President and Director of Container Ship Business at DNV, and Boris Bondarenko, DNV Regional Manager, an important conversion was completed in China in 2025, marking a significant step in the efforts to decarbonize the maritime industry.

The project included the retrofit of a nearly 400-meter mega-container ship, which was seven years old, at a shipyard in Shanghai. With a capacity of 20,000 TEU, this vessel became the first in its class to be converted to operate on methanol and represents one of the largest retrofits of a single vessel to low-carbon fuel in container shipping to date.

The significance of the COSCO Shipping Libra retrofit lies not only in its status as the "first" but also in what it enabled. The transformation of this technically complex mega-vessel demonstrated a plausible pathway for large-scale retrofitting to methanol.

As explained in the article, for COSCO Shipping, the decision to retrofit to methanol was both strategic and practical. While new vessels remain central to fleet renewal, the company recognized the need to also consider existing tonnage to achieve decarbonization goals.

"Retrofitting allows us to act now," says Zhang Jun, Safety Manager, Technology and Innovation Department at COSCO Shipping Lines, Co., Ltd. "But it also involves trade-offs that need to be understood and managed."

One visible consequence was a reduction in container capacity. To accommodate the methanol tanks and systems, COSCO Shipping Libra lost 456 TEU, which required careful reassessment of deployment planning and networks.

The availability and handling of fuel were also key factors. While methanol infrastructure is rapidly developing on major trade routes, it remains less mature than traditional fuels. Operational teams had to adapt to new bunkering procedures, safety protocols, and fuel management practices.

"At the operational level, the learning curve is real," explains Jun. "Crew training, maintenance planning, and fuel logistics must evolve together."

Since its re-commissioning, COSCO SHIPPING Libra has demonstrated stable operation on methanol, giving COSCO confidence in the technical solution. The dual-fuel capability allows the vessel to switch between fuel types as needed, offering flexibility in the early stages of deployment.

"The project showed that even very large modern container ships can be successfully converted," says Jun. "This changes our perception of the future fleet."