Ships move most of the world's goods on the dirtiest fuel there is

Alternative fuels made using renewable energy that can power large ships across oceans. Green ammonia and methanol can be produced anywhere with renewable electricity and stored like conventional fuel. Ships need engine modifications to use these fuels, but the technology is being developed and tested now.

Modern sailing technology that helps power cargo ships, reducing fuel consumption without eliminating engines entirely. This includes rigid sails, rotor sails, and kite systems that can be retrofitted to existing ships or built into new designs. Wind assistance can cut fuel use by 10-30% on many routes.

Fuel cell systems that convert hydrogen into electricity to power ships on shorter routes. This works best for ferries, coastal shipping, and vessels that return to the same ports regularly where hydrogen refueling infrastructure can be built. Range and hydrogen storage are still limiting factors.

Electrical connections that let ships plug into the local power grid while docked, instead of running their engines for electricity. This eliminates emissions and air pollution in port cities. Requires coordination between ports and shipping lines to install compatible equipment.

Systems that plan more efficient shipping routes and operations to reduce fuel consumption. This includes weather routing to take advantage of currents and avoid storms, speed optimization to find the most fuel-efficient pace, and better coordination of cargo loading and port scheduling.