The penny really dropped for Anthony Gurnee when he realised how much space it takes to store hydrogen as a fuel on vessels.

“The light-bulb moment came for us in talks with a company that was going to use containerised compressed hydrogen. The numbers were quite striking,” the Ardmore Shipping chief executive tells TW+.

The system meant you ended up with 450kg of the fuel in a 40-foot container weighing 40 tonnes, says Gurnee. Just enough to power a small ship for 20 hours.