There discloses a ubiquitous energy network for optimum utilization of energy, which includes nodes connected by an interconnected network architecture of virtual pipelines transferring a ubiquitous energy flow, with the ubiquitous energy flow being transferred among the nodes bi-directionally. The node includes a system energy efficiency controller, and at least one of other nodes, an energy generation device, an energy storage device, an energy utilization device, and an energy regeneration device connected to the controller. The controller controls the input and output of the ubiquitous energy flow of the at least one of the other nodes, the energy generation device, the energy storage device, the energy utilization device, the energy regeneration device. Furthermore, the node, an access terminal, a virtual tag, and the virtual pipeline of the ubiquitous energy network, and a server and method for providing energy transaction and service by the ubiquitous energy network are disclosed.