It could be 10 times cheaper for shipping to invest in fuel efficiency than paying for alternative fuels.

The ratio comes from a report by the Copenhagen-based Maersk Mc-Kinney Moller Center for Zero Carbon Shipping.

It has crunched the numbers based on the targets and checkpoints agreed on under the International Maritime Organization’s revised greenhouse gas strategy; the cost of the fuels and technologies; and factors such as the efficiency losses of alternative fuels — from the wind turbines generating green electricity to the fuel being burned in an engine.