Impacts of Large-scale Penetration of Non-industrial Cogeneration Systems on CO₂ Emission in Japan

Abstract

This paper presents a quantitative evaluation of CO₂ emission from grid power systems and heat source systems including CHP (combined heat and power) in residential and commercial buildings in Japan. We estimated changes in CO₂ emission from the utility grid and from CHP using an optimal generation planning model. Through quantitative simulation runs, the authors obtained the following results. First, introduction of CHP at a certain degree brings an increase of CO₂ emission until 2020 regardless of the pace of nuclear power development. Second, because CHP will defer highly-efficient AGCC (advanced gas combined cycle generation) due to suppressed demand growth of utilities in the daytime when most of commercial CHP systems operate. CHP can reduce CO₂ emission only if generating efficiency of CHP will be improved up to 50% or higher.