Financial Sustainability of Selected Rain Water Harvesting Systems for Single-Family House under Conditions of Eastern Poland

Abstract

Recent climate changes limiting the available water resources require careful sustainable water management in the cities, the locations of highest drinking water consumption and sanitary sewage and stormwater generation. Over 50% of water demand in the residential areas of cities cover activities in which non-potable water could be used, e.g., toilets and laundry facilities, cleaning, garden irrigation and washing vehicles. Thus, rain water harvesting (RWH) systems are the sustainable alternative water supply, lowering drinking water consumption, by the usage of non-potable harvested water, and limiting the anthropopressure on natural water reservoirs. However, in many cases the social acceptance of RWH and willingness to pay may be affected by financial sustainability, including the affordability and profitability of the investment. This paper presents a case study concerning the financial sustainability of thirteen designs of RWH systems for a single-family house under the climatic and economic conditions of Eastern Poland, one of the poorest regions of the European Union. The financial sustainability of the tested RWH designs were based on indictors of cost-efficiency: dynamic generation cost, payback period, net present value and benefit–cost ratio. The performed analyses showed the limited profitability of the studied RWH designs and the insufficient governmental financial support which may significantly affect the social sustainability of the designs under the local conditions.

A Hybrid vs. On-Grid Photovoltaic System: Multicriteria Analysis of Environmental, Economic, and Technical Aspects in Life Cycle Perspective

“…The profitable investment is characterized by the value of BCR indicator higher than 1 (BCR ≥ 1). BCR can be calculated from the following equation [31]:…”

Assessment of the Impact of Loss-of-Retention Fees on Green Infrastructure Investments

“…Stormwater fees are common in the U.S. and Canada, as shown by the latest survey from 2021 [55]. Research on stormwater fees has been the subject of many analyses of their impact on the development of green infrastructure, which proved their effectiveness; for example: (1) the assessment of stormwater fees in Germany (also noted as imperviousness fees) [56][57][58] showed a 10% decrease in the impervious area in Munich [56]; (2) Qiao et al, in two research papers [17,45], analyzed the governance factors of sustainable stormwater management and recommended the use of stormwater fees as an important incentive; and (3) analyses of stormwater fees in Poland were conducted in terms of their impact on the economic efficiency of green infrastructure [59][60][61], and they were also mentioned as important factors in the development of sustainable stormwater management [62,63]. Thurston et al analyzed auctions and fees as incentive methods, and concluded that relatively minimal financial incentives could encourage homeowners to retain stormwater runoff on their property [47].…”

Developing Generalised Equation for the Calculation of PayBack Period for Rainwater Harvesting Systems

“…One of the strong grounds behind it might be the investment cost [1]. This issue is considered as an important obstacle for most nations to the extent that many leading experts and researchers are of the belief that there is a strong link between sustainability of the RHSs and financial aspects of their construction [15,16]. The study of economic aspect of the RHSs by Dijk et al [17] indicated that strategically designed, financed, and implemented rooftop RHSs meet large-scale urban water infrastructure needs.…”

“…Regarding this fact, modelling and numerical calculations could address the associated issues. The economical sustainability of the RHSs designs for assessment of the affordability and profitability of the investment in the RHSs was studied by Musz-Pomorska et al [15] in Poland. In this survey the significance of the governmental financial support and restricted profitability of the RHSs were revealed.…”