Comparative Techno-Economic Feasibility Analysis of Solar Thermal Collectors for Domestic Hot Water Integration in Munitibar, Basque Country, Spain

Abstract

This paper presents a comprehensive comparative techno-economic feasibility analysis of four flat-plate solar thermal collector models for Domestic Hot Water (DHW) generation across four municipal buildings in Munitibar, Basque Country, Spain. The four collectors evaluated are: PROMATOP 1.5, PROMATOP 2.0, PROMASUN BLUE 2.0, and the Apricus FPC-A26. Solar irradiance and ambient temperature data for the summer month of June and the winter month of November were extracted from the Photovoltaic Geographical Information System (PVGIS). Collector efficiency calculations, useful energy output, collector spacing, solar fraction, CAPEX/OPEX analysis, payback period, and environmental impact (CO₂ reduction) are evaluated and compared. Results show that all four collectors significantly exceed the 110% monthly solar fraction limit set by the Spanish CTE regulation when the full roof area is utilized. The PROMASUN BLUE 2.0 offers the shortest payback period of 11.4 years and the lowest CAPEX at €62,850, while the Apricus FPC-A26 delivers the highest total energy output due to favorable roof fit. The PROMATOP 2.0 provides the best balance of efficiency, cost, and performance.