Economic Efficiency of Solar and Rainwater Systems—A Case Study

Abstract

The study deals with the analysis of data from a selected tourism facility and the implementation of a solar system and a rainwater system, which are an alternative to commonly used energy sources. The objective is to evaluate the potential savings from the use of the solar system for water heating and the rainwater system for purposes other than potable use with respect to local conditions of sunlight and rainwater variability. The facility holds 257 beds allocated in 124 rooms on 5 floors. The result of the contribution is an economic evaluation of the efficiency of investments in the proposed systems and the resulting recommendations in the field of energy flows in the selected facility. Appropriate formulas including the consumption of hot water, the amount of energy needed to heat water, the cost of the consumed energy necessary for heating and the average annual rainfall in the location, water consumption for clearly identified purposes of alternation with rainwater, the initial investment costs and operating costs of the solar and rainwater systems, were used for an economic evaluation of the investment into the solar and rainwater systems. Based on the economic evaluation, the economic efficiency of the proposed systems and the return on investment was calculated. The payback periods for the solar system used for hot water heating and the rainwater system used for non-potable purposes, accepting the local conditions, are 7 and 15 years, respectively.

The Use of Precipitation in the Cities of the Future—Problems, Barriers and Challenges

“…The weaknesses of the use of precipitation in the city include the high investment costs appearing in the case of introducing a more complicated installation, e.g., supplying water for flushing toilets. An example of the total purchase cost of this type of installation for the use of rainwater for a tourist in a Slovakia facility was EUR 10,535 (euros), and the return on investment in this case was 15 years [51]. In turn, the application of the methodology proposed in [52] for assessing the benefits of large-scale installation of domestic RWH systems in multi-storey buildings for the old town of Lipari (Aeolian Islands) showed that about a quarter of the installed RWH systems could potentially pay for themselves in less than 10 years [52].…”

“…The system should also be periodically inspected. The annual cost of maintaining the installation for the use of rainwater for the aforementioned tourist facility in Slovakia was approximately EUR 49 [51]. Energy consumption should be particularly taken into account when highly efficient methods, such as reverse osmosis, are used for rainwater treatment.…”

“…Weaknesses also include a small range of current uses of rainwater in housing; it can be used in households mainly for flushing the toilet and laundry [11,52], as well as for irrigation of household greenery [51]. However, it is possible to extend this scope in the future.…”

Differences in sustainable nutrition behaviour of different generations of Czech consumers

“…The economic domain is associated with the production and sale of output. Here, in conjunction with the environmental pillar, one can mention the area of, e.g., circular economy and the associated amount of waste produced by each sector (Petrariu et al 2022;Šimková et al, 2023;Bednárová et al 2023) or bioeconomy, which is discussed in the article by Oláh et al (2023).…”

Economic and Technological Advances of Green Energy and Sustainable Development: The Overview

“…The study of L. Bednárová, H. Pavolová, Z. Šimková, and T. Bakalár [6] is devoted to the research of the economic efficiency of alternative energy sources at the facilities of the tourism industry-a rain water system for non-food purposes and a solar system for heating the water, observed in specific geographical and climatic conditions (city of Košice, Slovak Republic). The study clearly showed that the rainwater collection system on individual buildings, including tourism facilities, is able to provide up to 60% of the average water consumption by visitors (an average of 110 guests per day, use for 3 months a year by 80%), taking into account the area of the roof as a water collector.…”