Methanol, batteries and hybrid propulsion: what are the key considerations?

To support vessel operators, Caterpillar has been developing pathways and roadmaps for drop-in fuels that can work with existing four-stroke, Diesel-cycle engine technology, as well as investing in new technologies to support the uptake of alternative fuels and improve fuel efficiency, lower opex costs, and reduce CO2 and greenhouse gas emissions.

Later this year, the company expects to have its first marine battery system on the water, according to Will Watson, Product Director, Caterpillar Marine. Mr Watson spoke to us following his participation in a panel, “Fuel transition and investment timing: From strategy to commitment,” at ITS 2026, Gothenburg, Sweden. During the panel, tug owners and operators, ship designers, shipbuilders, and propulsion specialists examined the key considerations in assessing alternative fuel investments, capex, and the technical, operational, and safety considerations of hybrid and battery propulsion.

In this interview, Mr Watson provides an update on Caterpillar Marine’s methanol dual-fuel engine and battery development, as well as key insights for tug operators.

The tug sector has been closely watching research underway at the US Department of Energy’s Oak Ridge National Laboratory (ORNL), Oak Ridge, Tennessee. Caterpillar has been collaborating with ORNL on developing a dual-fuel combustion strategy for a Caterpillar Marine engine to address the challenge of methanol ignition in diesel engines. The approach pairs methanol with a small amount of diesel used as a pilot fuel to start combustion, enabling methanol dual-fuel operation across a much wider range of conditions.