In Japan, during the last 20 years, combined heating and power (CHP) system has been developed rapidly. In order to grasp the present condition of introduction and the existing problems of CHP system, the questionnaire survey on CHP system had been carried out at Tokyo. According to the results of investigation, it can be summarized as follows: 1) CHP system had been used widely in various sectors. The generating electricity capacity ranged several ten to several thousands kilowatt. 2) The percentage of CHP total capacity to the electricity demand peak was low and the average value for all users investigated was only 25%. 3) Gas turbine and gas engine achieved 60%-80% overall energy utilization efficiency with 20%-34.5% generating electricity efficiency and 19.5%-50% exhaust heat utilization efficiency. 4) Education buildings had the maximum average generating electricity efficiency with 30.6%, followed by hospital buildings with 29.6%, amusement facilities with 29.5%, office buildings with 28% and compound buildings with 25%. Hospitals attained the maximum average exhaust heat utilization efficiency with 46.1%, followed by offices with 41.3% and compound buildings 39.8%. 5) Various users had different motivation of selecting CHP system. Both office and compound buildings selected economy as the most important reason introducing CHP system
while hospital and education users concerned more saving energy. Hospital and office users were satisfied with the CHP system introduced
while compound building users were not satisfied very much with the CHP system. © 2005, Architectural Institute of Japan. All rights reserved.