Abstract: In one aspect, a cloud cube for providing energy efficient cloud computing is disclosed, which includes: an internal DC bus for transferring energy, clusters of computing servers coupled to the internal DC bus for performing cloud computing, at least one NAS storage coupled to the internal DC bus, at least one energy storage coupled to the internal DC bus, a plurality of energy sources coupled to the internal DC bus, and at least one energy manager coupled to the internal DC bus for performing energy management or energy routing. In another aspect, a system for providing energy efficient cloud computing is disclosed, which includes: a DC grid having a plurality of interconnected energy sources, and a plurality of cloud cubes connected by the DC grid such that energy can be routed and shared among the cloud cubes.