A report published by reports on 17 September 2026 warns that choices made now over ship engines will determine which fuels are technically available to the fleet in 2050, while the cost and availability of fuels will decide what ships actually burn.
The analysis underlines a stark reality of shipping’s asset base: vessels typically remain in service for between 25 and 30 years, and only about 4 per cent of the global fleet is replaced each year. Those two facts combine to give shipowners a narrow window in which newbuild decisions have disproportionate long‑term consequences.
Because only a small fraction of tonnage is renewed annually, the report notes that engine selections on new ships ordered over the coming decade will establish much of the engine capacity that still exists in 2050. In other words, investment in propulsion hardware today sets the technical envelope for future fuel options.
However, having the physical capability to use a fuel is not the same as that fuel being consumed at scale. The study emphasises that fuel economics will govern uptake; owners will deploy the fuel that is affordable, available and compatible with their commercial model.
Asset life and the timing of decisions
The long service lives of merchant ships mean that a decision to install a particular engine type is effectively a multi‑decade commitment. That reality increases the stakes of choices made now by yards, engine manufacturers and buyers, according to the report.
Because it is not feasible to replace the majority of the fleet quickly, the report argues that the pattern of engine types on newbuildings over the next ten years will largely shape which fuels can be consumed by 2050. The implication is that early decisions will constrain future options.
Economics will decide consumption
Even with compatible engines fitted, the report cautions that vessel operators will be guided by price signals and supply realities when selecting between fuels. Fuel cost, availability and the operational flexibility required by a ship’s trade will determine what is actually burned in practice.
The paper highlights dual‑fuel installations as one practical response to present uncertainty. Dual‑fuel engines allow shipowners to switch between conventional fuels and alternative options, providing flexibility while keeping vessels operational if one fuel becomes scarce or costly.
The report stops short of predicting which specific fuels will prevail. Instead it sets out a framework: technical capacity shaped by newbuild engine choices, and commercial decisions shaped by fuel economics, will together determine the fuel pathways that emerge by mid‑century.
Industry stakeholders are left with a policy and investment dilemma. Engine makers, yards and owners must weigh the costs and risks of choosing technologies now that may lock in fuel choices for decades, while fuel producers and regulators must consider how markets and incentives will affect uptake.
The reports analysis makes clear that the timing of investment matters as much as the technology itself. With a limited annual renewal rate and long asset lives, the next ten years are presented as decisive for the propulsion mix available in 2050.