Exergetic, enviroeconomic and exergoeconomic (3E) assessment of a stationary parabolic trough solar collector with thermal storage

A solar heating system operating in thermosyphon regime was experimentally evaluated in this study. The system consisted of a stationary parabolic trough solar collector (PTC) with thermal storage. The effect of three collector inclination angles (0 degrees, +5 degrees, and +10 degrees) and two thermal fluids (water and thermal oil, denoted as WPTC0 degrees and OPTC0 degrees) were evaluated on the exergetic, enviroeconomic, and exergoeconomic (3E) performance of PTC. The average exergetic efficiencies for the evaluated cases were 10.84, 11.75, 12.97, and 19.73% for WPTC+10 degrees, WPTC+5 degrees, WPTC0 degrees, and OPTC0 degrees, respectively. It was observed that about 50% of the input exergy is lost in all cases evaluated, indicating that some improvements could be incorporated to recover part of this loss. WPTC0 degrees had the lowest average destroyed exergy among the inclinations (35%). For the case using thermal oil, the average exergy destroyed was 28%. OPTC0 degrees showed the best results in exergetic terms. OPTC0 degrees also presented the highest values of the exergoeconomic parameter among all the evaluated cases, and WPTC0 degrees presented the highest values among the evaluated inclinations. The energy and carbon payback times obtained were 0.848 and 0.569 for the WPTC0 degrees and 0.923 and 0.608 for the OPTC0 degrees, respectively.