SERVER AND POWER MANAGEMENT METHOD

A server that manages energy of a power grid by using a plurality of energy storage resources includes a loss obtaining unit and a selector. The loss obtaining unit obtains for each of the plurality of energy storage resources, energy loss including retention loss and input and output loss, the energy loss being caused in storing energy in each energy storage resource. When surplus electric power occurs in the power grid, the selector selects at least one energy storage resource for storing surplus electric power from among the plurality of energy storage resources based on the energy loss caused in storing surplus electric power.