The Application of Photovoltaic Systems in Sacred Buildings for the Purpose of Electric Power Production: The Case Study of the Cathedral of St. Michael the Archangel in Belgrade

In light of climate changes, technological development and the use of renewable energy sources are considered very important nowadays, both in newly designed structures and reconstructed historic buildings, resulting in the reduction in the commercial energy consumption and CO2 environmental emissions. This paper explores the possibilities of improving the energy efficiency of sacred heritage buildings by utilizing photovoltaic systems. As an exceptionally significant cultural good, the Cathedral of St. Michael the Archangel in Belgrade shall serve as a case study, with the aim of examining the methods of mounting photovoltaic (PV) panels, taking into account the fact that the authenticity and the aesthetic value of this cultural monument must remain intact. A comparative analysis of the two options for installing PV panels on the southwestern roof of the church was performed using simulations in PVgis and PVsist V6.84 software, with the aim of establishing the most efficient option in terms of power generation. The simulation results show that photovoltaic panels can produce 151,650 kWh (Option 1) and 150,894 kWh (Option 2) per year, while the required amount of energy is 42,726 kWh. The electricity produced exceeds the electricity requirements for the decorative lighting of the Cathedral Church, so it can be used for other purposes in the sacred complex.This article belongs to the Special Issue Preventive Conservation and Energy Efficiency of Heritage Building

Experimental Investigation of Thermal Properties of Frozen Tap, Demineralized, and Sea Water

This paper reports an experimental investigation of the thermal properties of frozen tap, demineralized, and sea water. The presented research assists in a better understanding of the thermal properties of ice and the processes within it and contributes regarding the generation of novel experimental data. The thermal conductivity was measured in a range from −14 °C to −33 °C using the Transient Plane Source (TPS) method. Ice blocks were placed in an expanded polystyrene box in the freezer, which is where the measurements took place. The thermal conductivity of the tap water ice was observed to vary in a range from 1.915 ± 0.005 Wm−1K−1 at −14 °C to 2.060 ± 0.004 Wm−1K−1 at −33 °C. The values obtained for the ice made of demineralized water differed by less than 10%. The thermal conductivity of the sea ice was shown to be more temperature dependent, with the values ranging from 1.262 ± 0.005 Wm−1K−1 at −14 °C to 1.970 Wm−1K−1 ± 0.004 at −33 °C. A noticeable fall in the thermal conductivity of the sea ice was observed in the temperature range from −26 °C to −19 °C. A possible reason for this could be the increased precipitation of salt in that temperature range. Measurements of thermal diffusivity displayed similar trends as those of thermal conductivity. Specific volumetric heat capacity was indirectly calculated