Without a crew on board, a cargo ship could run on 10 to 15 percent less fuel and cut its carbon emissions by a similar percentage, according to Oskar Levander, vice president for innovation at Rolls Royce, which is developing autonomous ships with researchers at VTT Technical Research Centre of Finland. "The primary benefits of remote and autonomous vessels will be improved efficiency and safety," Levander told the blog Climate Home. Driverless cargo ships, by contrast, would be responsible mostly for steaming across the ocean, docking, loading or unloading cargo, then steaming on to the next port. And Rolls Royce says its researchers are perfecting the technologies needed to remotely steer ships through the high seas.
The key is combining into a single system two well-known technologies: coal gasification and fuel cells. The heat leads to chemical reactions that release gases from the coal particles -- mainly carbon monoxide and hydrogen, both of which can produce electricity in a solid oxide fuel cell. In the fuel cell, a membrane separates the carbon monoxide and hydrogen from the oxygen, promoting an electrochemical reaction that generates electricity without burning the fuel. In comparison, the proposed combined gasification and fuel cell system could achieve efficiencies as high as 55 to 60 percent, Ong says, according to the simulations.