Waiting for the "modern world´s first 100 per cent fuel free sailing cargo ship"

The World Maritime News tells us that "Development is underway to design the modern world’s first 100 per cent fossil fuel free sailing cargo ships":

With rising fossil fuel prices and the global challenge of reducing greenhouse gas emissions, this project is set to change the shipping industry by providing efficient and affordable low-carbon shipping. The project combines proven technology, using the state of the art dyna-rig sail propulsion system with an off the shelf Rolls-Royce engine powered by waste derived liquid biomethane (liquid gas).

The ships are being developed by B9 Shipping, part of the B9 Energy group of companies, which has started work on a full-scale demonstration vessel validating the engineering and economic assumptions of the initial vessel design.

The fundamental testing programme is being conducted at the University of Southampton’s Wolfson Unit for Marine Technology and Industrial Aerodynamics (WUMTIA), which has provided innovative marine technology and industrial aerodynamics expertise for over 40 years to a world-wide customer base.

Diane Gilpin, Director of B9 Shipping, says: “The shipping sector is a highly complex, interconnected system and our task has been to develop relationships with key players across the industry. Having worked previously with WUMTIA, I believe this collaboration will enable a robust, commercially and technically viable solution to be ready for scale once the engineering is proven.”

Wouldn´t it be nice to return to the age of great commercial tall ships? Why not, but before all sail enthusiasts are carried away by the promises, they should understand that the essential piece of information here is: "once the engineering is proven". So far none of the new "revolutionary" cargo sail ship technologies have been even remotely successful, and it is doubtful whether this one will be, either. 

And looking at the picture, one might be entitled to ask, where the inventors of the new "fossil fuel free sailing cargo ship" are planning to put the containers, which are the backbone of modern cargo shipping?