A system (20) is operable in a plurality of modes. The system has: a container (22) having an interior (24); an internal combustion engine (66); a refrigeration system (30) and a flywheel energy storage device (70). In at least one mode, the refrigeration system coupled to the internal combustion engine to receive power and thermally coupled to the container to cool the container interior. In at least one mode, the energy storage device coupled to the internal combustion engine to receive power from the internal combustion engine. In at least one mode, the energy storage device coupled to deliver power to the refrigeration system.