Tracking system, tracking method, and recording medium

A method, comprising:

• in response to supply information indicating a supply of energy by a supplier, generating first information for tracking energy that instructs generation of second information, the second information indicating an owner of the energy and a production method used for producing, the energy:
• in response to usage information indicating usage of the energy by a user, determining whether ownership of the energy in the second information has not been changed from a previous owner to the user;
• and
• based on a determination that the ownership of the energy in the second information has not been changed, generating other first information for tracking energy that instructs a change of ownership of the energy in the second information from the previous owner to the user.

A non-transitory computer-readable medium encoded with computer-readable instructions that, when executed by a processor, cause the processor to perform a method of tracking exchange of energy, the method comprising:

• in response to information on supply of energy by a supplier, generating first information for tracking energy that instructs generation of second information, the second information indicating an owner of the energy and a production method used for producing the energy:
• in response to information on usage of the energy by a user, determining whether ownership of the energy in the second information has not been changed from a previous owner to the user;
• and
• based on a determination that the ownership of the energy in the second information has not been changed, generating other first information for tracking energy that instructs a change of ownership of the energy in the second information from the previous owner to the user.