抄録
Carbon-related energy (CE), which is the concept proposed by the authors, is defined as proportional distribution of fossil energy (FE) by the ratio of heating value of carbon to heating value of carbon and hydrogen included in fossils. In the study, by applying the CE-related concepts to equations based on Kaya identity, the following results were obtained. (1) CO2 emissions is very highly correlated to the CE calculated using higher heating values (HHV) as well as using lower heating values (LHV). (2) The CE ratio to primary energy (ENE) in Japan was changed by increase of RE ratio (mainly hydro power, approximately 14 pp) in 1960s, by increase of NE ratio (approximately 14 pp) between 1970 and 1990, and by decrease of NE ratio (approximately 13 pp). Since the CE ratio to fossils (FE) in Japan has been stable since 2000, the change of the CE has been approximately equal to the change of fossils (FE). (3) The change of fossils (FE) in the future can be managed by the sum of the change of primary energy (ENE) and the change of (FE/ENE) regardless of the value of primary energy conversion factor (rsp) of non-fossil electricity if the rsp is intertemporally stable. (4) When the rsp of non-fossil electricity is assumed less than the inverse of fossil power generation efficiency, the replacement of fossil electricity by non-fossil electricity causes the decrease of primary energy, which is consistent with a typical target of energy savings of annual decrease of primary energy.
