Global warming, fossil fuel shortage, and environment pollution are a growing concern on concentrated solar power (CSP) because of the largest amount of energy resource. Parabolic troughs and power towers are state-of-the-art commercial technologies. The primary drawbacks of current CSP technologies are low thermal efficiency and high investment cost. In the current study, a novel CSP system is proposed. This system integrates a solar parabolic trough power system and a solar tower power system. In this hybrid system the tower collectors with high concentration ratio generate high-temperature heat at 574 °C, and the trough collectors with a relative low concentration ratio generate mid-temperature heat at 390 °C. The mid-temperature heat from trough collectors generates steam up to 370 °C. The steam is then superheated and reheated by the high-temperature heat generated by the tower collectors. Compared with an individual solar trough plant, the temperatures of the primary and reheated steam are increased from individual trough plant’s 370 °C in the individual trough plant to 535 °C in the hybrid system, thus increasing the conversion efficiency from heat to power. Based on the simulation results, the annual thermal efficiency of the hybrid system can reach 15.84%, higher by 1.77 and 2.29 percentage points compared with those of the individual solar trough and tower plants. The electricity generation cost of the new system can be decreased by 7.5% to 12.4% compared with that of the individual trough or tower plants. The results obtained in the present study provide a new approach for utilizing solar energy more efficiently and more economically.
A novel concentrated solar power system using cascade steam-organic Rankine cycle and two-stage accumulators
