EFFECT OF FLUCTUATION OF HOT-WATER DEMAND ON ACTUAL PERFORMANCE OF HOME CO-GENERATION SYSTEM

摘要

This paper discusses the efficiency of a micro co-generation system (μCGS) for residential use based on the hot-water demand observed in three domestic households. Two structures of μCGS were assumed, i.e., PEFC with a large backup boiler and small hot-water tank, and PEFC with a small backup boiler and large hot-water tank. Assuming the constant output operation of a PEFC, we calculated the required output of a backup boiler in order to meet a series of hot-water demand for each month during the period between August 2000 and March 2001. We evaluated the composition of the hot-water output on the supply side and the hot-water usage on the demand side. As a result, although the backup boiler supplied the hot water, some hot-water output of PEFC was wasted because of the concentrated hot-water demand within a short period. This reduced the actual efficiency of μCGS by 10% or more in each month as compared to the ideal situation, where all hot-water demand was met by only the hot-water output from PEFC and no hot-water output was wasted.