Proposal of Linear Approximation of Household Fuel Cells and Small-Scale Community Energy Management System

The use of Solid Oxide Fuel Cells (SOFCs) continues to spread in Japan. This paper clarifies the simple linear relation between their gas consumption and their generated electric power. This means that the total amount of gas consumption only depends on the total electric power, even if plural SOFCs operate in parallel. The total gas amount doesn´t depend on SOFC power distribution. To realize parallel SOFC operation, this paper presents a new current transformer (CT) circuit that realizes equal power distribution. This paper also proposes a small-scale Community Energy Management System (CEMS), where three houses share two SOFCs and one battery cell. The electric consumption of each house is hidden from the other houses to protect privacy in the proposed system. To evaluate our proposed system, a prototype CEMS was implemented, where the SOFCs and a battery cell were simulated by software. Finally, we introduced a prototype CEMS into three actual houses and conducted a social experiment that shows that providing low-priced electricity generated by a SOFC changes user awareness of energy usage and promotes energy reduction.