Advancing solar thermal energy systems: Comparative study of low-cost receivers in parabolic trough collectors.

This article focuses on the experimental evaluation of two low-cost receiver designs for parabolic trough collector (PTC) solar thermal systems equipped with stainless-steel reflectors, using the International Organization for Standardization (ISO) 9806:2017 standard for thermal performance testing. The study compares a U-pipe receiver and an inlet/outlet pipes receiver, finding that the inlet/outlet design achieves higher thermal efficiency (49.77% at 25 °C) and lower heat loss coefficients than the U-pipe receiver (43.79% at 25 °C), attributed to increased heat transfer surface area and direct water-absorber contact. Both receivers exhibit decreased efficiency at higher operating temperatures, but the inlet/outlet configuration maintains superior performance and reduced overall heat losses, making it a promising cost-effective solution for developing regions. An economic analysis scaling the prototype to commercial size indicates a 33% cost reduction compared to existing systems, with a break-even period of approximately 2.3 years, highlighting the design's potential for accessible solar thermal energy applications.