Automated transport systems/Automated, zero-emissions ships
An autonomous, clean cargo ship is feasible with currently existing technology. As it would have no fuel or crew costs, even a higher initial construction cost than normal cargo ships would be justified.
Ships are comparatively easy to automate, as there are not many things to bump into out at sea, and they do not have to deal with the high-speed manoeuvering that has challenged designers of autonomous helicopters and cars. There are plenty of small unmanned military boats (USVs for 'unmanned surface vehicles' in military-speak) in operation already, though this technology has not been much applied outside of the military nor on larger boats. With GPS, it is very easy for a ship to be programmed to go from anywhere to anywhere else. Loading and unloading cargo ships has become more and more automated since the 1950s and it is now possible to get containers off ships and into trucks without any human labour.
There is an abundance of clean energy available at sea. The large surface area of a ship provides ample space for sails and solar panels, and wave power can also be harnessed.
There are several ways to make ships more energy-efficient. One is to design large catamarans, which tend to use less fuel than monohulls of equivalent size. Catamarans tend to rock more than monohulls, though this may not be a problem for many cargo ships. Trimarans, if properly designed, can offer both the efficiency of a catamaran and the stability of a monohull .
Sail-power is making a comeback in commercial shipping. It makes commercial sense to avail of a free source of energy and sails can now be computer-controlled to automatically turn to the angle that best catches the wind. and run completely autonomously, adjusting themselves to the changing winds.
Although there are designs for large cargo ships with zero emissions and small autonomous boats with zero emissions , there are not yet any designs for large, autonomous, zero-emissions cargo ships. Time for an open-source design project, perhaps?