Solar–Thermal Systems for Domestic Hot Water Production Implemented in Collective Households

Abstract

The energy used in the built environment represents approximately 40% of the total energy consumed by the community, with significantly higher values in rural communities. Out of this, a significant share is used for heating, cooling, and domestic hot water (DHW) production. Therefore, identifying renewables-based thermal energy production systems represents an essential step in the transition toward the status of sustainable communities; however, their wide spread has to be supported by efficiency and a high social and economic acceptance. The use of renewable energies in collective households is currently facing certain technological and financial barriers; therefore, acceptable and affordable implementation needs to be stepwise designed by (partially) involving the already existing infrastructure. Technical and economic feasibility is supported by accurate design that considers the local variability of the renewables’ potential and consumption. In a first step, renewables-based DHW production can be considered because this is relatively constant throughout the year, and solar–thermal systems represent good candidates because there already exists a high degree of acceptance at the community level for this type of system. This paper presents a novel methodology for the design of solar–thermal systems implemented in rather small communities, considering the actual energy consumption for DHW production in collective households (based on the local solar energy potential; the methodology targets the identification and use or extension of energy production and distribution systems). A case study (Taberei District in Odorheiu Secuiesc City, Harghita County, Romania) is detailed, allowing technical analysis and feasibility assessment and also considering affordability and sustainability.