First, let's clear up where the shipping containers fit in. The taller central section (which is clearly wedge-shaped in plan view) is not a container. Nor is it fashioned from parts of containers. No, this specially-constructed space houses the living and dining areas, with some storage space above.
But two containers flank this central living space on either side, and these make up the Shipping Container House's bedrooms and home office spaces - as well as the kitchen judging by the interior photography.
If the Shipping Container House does indeed constitute an entirely off-grid abode then this is the design's main achievement - incorporating passive (i.e. non-mechanized) design approaches such as passive cooling and green roofs, while the building's orientation and window design has attempted to minimize solar heat gain (the house is located in Colorado USA). It also appears some form of exterior cladding has been applied to the containers themselves in an additional effort to mitigate solar heating.
Power is provided by a pellet stove (so though the house may be off-grid, it isn't entirely self-sufficient) and on-site photovoltaic solar power.
Previously on Gizmag, and potentially of interest to the container-inclined, the Port-a-bach shipping container mobile home, APHIDoIDEA's 65-container education center plan, and Tsai Design's shipping container classroom.