Economic potential analysis of rainwater harvesting systems with introduction ofnon-potable water tariffs

学生名：解 画粤

研究テーマ：Economic potential analysis of rainwater harvesting systems with introduction ofnon-potable water tariffs

入学年月:2021.04

修了年月:2023.03

取得学位：修士（工学）

論文概要:Water scarcity, particularly in urban areas, poses significant challenges to social and economic development while threatening human well-being. Rainwater harvesting systems (RWHs) offer an effective solution by enabling on-site rainwater reuse to meet non-potable water demands in buildings. This study evaluates the advantages, limitations, and economic feasibility of RWHs, proposing a comprehensive evaluation and optimization model to enhance their performance and adoption.

Chapter 1 introduces the research background, highlighting global and urban water scarcity, with a focus on Japan’s water conservation measures. The necessity and advantages of decentralized water reuse systems are discussed, alongside a literature review of RWHs. Current evaluation methods are criticized for idealism, and the economic impact of RWHs on main water utilities is noted.

Chapter 2 details the components and configurations of RWHs, emphasizing their optimization for this study. It outlines system elements, including disinfection equipment, and describes the study area and the RWH system employed.

Chapter 3 proposes a simulation model for RWHs based on the widely used water balance model and its "Yield After Spillage" (YAS) algorithm. This model, coded in MATLAB, was applied to a campus RWH system in Japan, demonstrating high accuracy in simulating performance and scale. Economic evaluations, including electricity consumption and life-cycle cost analysis, were conducted to assess feasibility.

Chapter 4 introduces an economic optimization model using cooperative game theory to address the economic challenges of RWHs. Results show that cooperative frameworks and government subsidies enhance the economic viability of RWHs by reducing construction costs and aligning incentives between RWHs and water utilities. A non-potable water tariff scheme is proposed to improve adoption.

Chapter 5 summarizes the findings and outlines future research directions, emphasizing the potential for RWHs to alleviate urban water scarcity through optimized and economically feasible implementations.