In some embodiments, an electric energy information provision method includes measuring electric energy, analyzing the measured electric energy to generate electric energy information, and displaying the generated electric energy information in response to a request of a user. The electric energy information may include a variation status, a standard deviation analysis result, a dispersion deviation analysis result, trend line information, past accumulative electric energy variation information, anticipated future accumulative electric energy variation information, an electric energy usage status diagnosis, and electric energy reduction plan information.