Abstract
This article deals with Life Cycle Assessment (LCA) of warm water supplying system. LCA is an objective process to evaluate environmental burdens associated with products or processes, to assess the impact of them, and to evaluate and implement opportunities to affect environmental improvements. For the purpose of reducing energy consumption, we propose the warm water supplying system, which collects waste heat from electric power plant in operation, and transports it to existing waterworks system. Utilizing this system, we will be able to cut down the fuel for boilers especially in winter without huge initial investment.We investigate the existing waterworks and thermal power plants around Tokyo, and estimate the effects of energy saving through a year, taking account of pressure loss, temperature descent, increase of fuel consumption at thermal power plants and burden of construction. The result shows that this system can save primary energy consumption and reduce CO2 emission by almost 0.5-1% in Tokyo. In conclusion, this system is effective to save energy without large-scale newly construction.