A power management system includes an output facility configured to output output power with environment additive value and a consumption facility. The system further includes: a first receiver configured to receive, from the output facility, a message including an information element indicating the output power, a second receiver configured to receive, from the consumption facility, a message including an information element indicating consumption power consumed by the consumption facility, and a controller configured to identify the output power occupied in the consumption power and identify alternative power corresponding to a power loss, based on the power loss occurring on a power path from the output facility to the consumption facility. The controller is configured to identify the environment additive value corresponding to the output power occupied in the consumption power without based on the power loss.