2007 Volume 127 Issue 9 Pages 987-993
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.