Selection of a reliable energy source suppling domestic hot water (DHW) system in the kindergarten – a case study

Abstract

Renewable energy sources (RESs) are used more and more frequently as energy sources for heating and domestic hot water (DHW). However, there are many factors influencing the energy efficiency, thus also ecological benefits. Before making a decision what kind of RES is useful and reliable, a comprehensive analysis should be conducted taking into account technical, financial and ecological factors. This paper discusses different variants of energy sources that could be applied in a kindergarten building for preparing hot water, in place of existing solution (district heating system, DHS). An air heat pump (AHP) with photovoltaic panels (PV) were considered the most reliable energy sources in the analysed building, in terms of economic and environmental considerations. The simple payback time (SPBT) for this investment was estimated as 14.55 years. This solution causes the lowest CO2 emissions. Another system with solar collectors supplying hot water preparation in the heat center can be also recommended. The simple payback time in this case was slightly higher (14.94 years) and what is more, a decrease in CO2 emissions was observed compared to the actual conditions.