Solar can help shipping go green

From a distance, the yellow-and-blue ferry docking at the pier resembles the scores of other vessels that hop between Hong Kong's outlying islands and the peninsula every day.

But a closer look as passengers disembark reveals a grid of gleaming solar panels on the ferry's roof and, instead of the usual throbbing engine noise, there is a barely audible buzz.

The Solar Eagle and three similar vessels shuttle golfers to tee off on an 18-hole island course. Together they form the world's first hybrid powered ferry fleet and a commercial proving ground for technology that could transform the future of marine travel.

Electricity created by the solar panels and stored in a battery powers the engine while the vessel comes in and out of the harbor. Once out in the open ocean and a faster clip is required, the diesel kicks in.

One of the fleet, the Solar Albatross, sports two sails covered in solar panels that can be raised to harness both the sun and the wind to further reduce reliance on fossil fuel.

Robert Dane, Solar Sailor's founder, says that the technology offers ship owner huge fuel savings and has the potential to be used on all types of vessels from humble ferries and luxury super-yachts to bulk carriers shipping iron ore and navy patrol ships.

"I think in 50 to 100 years, all ships will have solar sails," he says.

"It just makes so much sense. You're out there on the water and there's so much light bouncing around and there's a lot more energy in the wind than in the sun."