Abstract
In order to spread economically viable distributed generation systems for apartment buildings, it is essential to develop an
efficient and low-cost heat supply system. We are developing a new cogeneration system (Neighboring Co-Generation
system: NCG). The key concept of this system is to install a heat storage unit with a hot water supply and a room heating
function at each household and to connect heat storage units by a single-loop hot water pipe. In this study, a dynamic
simulator was developed on the NCG system with solar heat utilization, and the environmental load reduction effects of solar
heat utilization in the system were evaluated under the condition satisfying the whole heat demand. The simulated results for
the system of 50 households showed that the annual use of the primary energy was reduced by 18 % in the case that a gas
engine was used as the main generator. When a SOFC system with the higher thermal efficiency was installed, the reduction
ratio increased to 29 %.
