Analysis of Greywater Recovery Systems in European Single-Family Buildings: Economic and Environmental Impacts

Abstract

This study explores the integration of greywater recovery systems (GRSs) within single-family buildings across European countries. The analysis evaluates the impacts of these systems from multiple perspectives: potable water conservation, economic feasibility, energy consumption, and environmental impact. Employing life cycle cost (LCC) and net present value (NPV) analyses, the research assesses the economic viability of these systems compared to standard water installations. Positive NPV is observed in countries such as Belgium, Germany, Denmark, Finland, and Norway, according to the base scenario. Additionally, the implementation of subsidies can enhance economic incentives for adopting GRSs by reducing the payback period (PBP). Significant findings include reductions in potable water demand by up to 43.0%, and energy savings of up to 42.6% are also observed with the use of GRSs. Additionally, notably lower carbon dioxide emissions (CDEs) were reported, with reductions being directly proportional to the decreases in energy use. This holistic approach aims to establish frameworks for decision-making processes, emphasizing that economic and environmental aspects are mutually complementary and significant.