Method to estimate long‐term change of heat and electric power daily load curves in Japan

The rapid spread of CHP systems will put pressure on the regional power system to require an examination of the power and heat output of CHP systems. When considering the countrywide potential of the CHP system, one should examine such a system in coordination with the grid power system. It is essential to calculate the heat and power demand at end-use level. In this paper, annual heat and power demands of end-use sectors are forecast to the year 2025 based on 20-year data. Regression analysis is used. Estimated annual demands are divided into the seasonal hourly demands considering demand characteristics. Daily load curves of heat and power demands are determined for the Japanese end-use sectors, and the annual changes of such demands are shown by duration curves of heat-to-power ratios. Moreover, the grid power daily load curves are computed numerically from the estimated heat and power demands for the manufacturing, residential, and commercial sectors. Such load curves also consider self-generated power for the manufacturing industry and self-consumption of the grid power. Estimating heat and power demands allows for a joint analysis between the power system and the future phasing in of CHP systems. © 2005 Wiley Periodicals, Inc. Electr Eng Jpn, 153(3): 18–30, 2005; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/eej.20162