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.

Hybrid photovoltaic installations, defined as on-grid PV system in cooperation with battery energy storage system (BESS), are still rare among the typical investors because the investment cost of the hybrid installation is significantly higher than the one of the on-grid system. However, while considering the broader perspective, such as environmental or technological aspects, the mentioned solution can be competitive with photovoltaic on-grid systems and therefore should be carefully tested in the widest possible context. In this study, the authors compared 3.05 kW of peak power hybrid and on-grid installations operating in temperate climate conditions (Eastern Poland) using economic indicators, such as dynamic generation cost (DGC) and benefit–cost rate (BCR); environmental impact indicators (IMPACT 2002+ and GWP 100a) determined using Life Cycle Assessment (LCA); and technological aspects consideration, including the reliability of examined systems. Creating a ranking of the considered solutions based on the equal weighting factors assigned to the appropriate features allows indicating the technological areas where the competitiveness of hybrid systems justifies the increased investment costs. One such area is business, where the economic criterion, the only negatively assessed one in the standard operation, can be radically changed by the possible financial losses due to interruption of energy supply.

Over the past decades, clean and renewable energy has become a subject of great interest to both science and industry in response to the pollution caused by conventional energy sources. Its useful form should always meet the requirements of high performance and low environmental impact, while remaining within the scope of the expected functionality. The purpose of study presented in this paper was to determine the operational characteristics for a recently developed photovoltaic (PV)-powered thermoelectric (TE) cooling system with heat recovery. The characteristics of operation of the tested system were determined within the use of a specially developed measurement system. The conducted experimental research allowed describing the conditions of power supply for TE module using PV system, calculate the coefficient of performance (COP) for the whole TE cooling system with heat recovery and calculate the environmental impact indicators based on the material and energy balance used for life cycle assessment (LCA).

This paper presents a numerical assessment of the influence of green roofs applied in the urbanized catchment on the rainwater outflow hygrogram as well as costs and economic efficiency analysis of the proposed green architecture application. The campus basin of the Lublin University of Technology, Poland, was selected as the object of the study. Three variants of extensive green roof applications were designed. The numerical model of surface runoff was developed in US EPA’s SWMM 5.2 software. The simulations were performed for three different rainfall events of various intensities and durations. The cost efficiency of the proposed green architecture was assessed by the Dynamic Generation Costs indicator, while economic effectiveness was tested by Benefits–Costs Ratio and Payback Period determined for all assumed variants. The determination of economic efficiency indicators was based on investment and maintenance costs estimation, assumed discount rate, and time duration of assessment. Results of numerical calculations showed up to 16.81% of peak flow and 25.20% of runoff volume reduction possibly due to the green roof application. All proposed variants of green roof applications in the studied urbanized catchment were assessed as generally profitable due to possible financial benefits related to heating and cooling energy savings and avoiding periodical change of bitumen roof cover.

Sustainable rainwater management may counteract the effects of climate change and significantly improve the distorted water balance in urbanized catchments. However, despite the hydrologic advantages of rainwater management, acceptance and willingness-to-pay in the local society are required. This paper presents an assessment of the financial aspects, i.e., the cost-efficiency and economic feasibility, of various designs of rainwater management for a small-scale urban housing community in Lublin, Poland. The research was performed for a housing community covering approx. 1.38 ha and five multi-family residential buildings. The proposed designs covered rainwater harvesting systems, supported with extensive green roofs, with rainwater retained in underground or above-ground reservoirs, used with variable demand for watering the green areas and for underground parking lot flushing. For each designed variant, the investment as well as operation and maintenance costs were estimated. The assessment of the cost-efficiency and profitability of the proposed rainwater management systems was based on three indicators: Dynamic Generation Costs, Payback Period and Benefits–Costs Ratio. The performed calculations showed that only two designs, utilizing above-ground rainwater reservoirs, could be assessed as economically profitable. Thus, local communities may be unable to financially sustain investments in sustainable rainwater management, so it seems that financial support is required.

The road construction sector is significantly material- and energy-consuming. In recent years, the pursuit of sustainable practices has led to growing interest in the use of recycled materials to reduce the environmental impacts of asphalt mixtures. However, there is a lack of comprehensive...