A Study on Reverse Power Flow from Home Cogeneration System

摘要

This paper discusses reverse power How from a home cogeneration system (H-CGS) in terms of energy conservation and influence on electric power systems. Data for actual electricity and hot-water demand observed in a family including two adults and two children for a year were used as a case study for a typical installation. When the reverse power flow is allowed except for during late night, in consideration of the influence on the electric power system, the reduction in annual primary energy consumption can be increased by about 40% relative to that in the operation without reverse power. The reverse power flow is large during the daytime in winter season, because the power output of H-CGS is large in order to meet the large hot-water demand. Even if reverse power is allowed throughout a day, the primary energy conservation is almost the same as that in part-time reverse power operation, while the reverse power during late night is as large as that during daytime. Finally, the economic value of reverse power flow as a measure for reducing CO_2 emission was evaluated. The result shows that the economic value of reverse power flow in PR operation corresponds to 23,000 yen/t-C.