Techno-economic feasibility assessment of parabolic trough solar collector in concentrated solar power plants using various heat transfer fluids

The selection of appropriate Heat Transfer Fluids (HTFs) for Concentrated Solar Power (CSP) plants is critical for optimizing performance, economic viability, and environmental sustainability. This study systematically assesses the technical, economic, and environmental feasibility of CSP plants using various HTFs in Benin City, Nigeria, through simulations conducted with the System Advisor Model (SAM). We compare the performance, financial, and environmental metrics of 30 MW and 60 MW CSP plants utilizing seven HTFs, including HITEC Solar Salt, HITEC XL, Therminol 59, Therminol 66, Pressurized Water, CALORIA HT 43, and Therminol VP-1. For the 30 MW plant, HITEC Solar Salt delivered the highest annual energy output of 103,957,136 kWh-e and a capacity factor of 44.0 %, despite having a higher Levelized Cost of Energy (LCOE) of $0.11/kWh. Conversely, Pressurized Water exhibited the lowest LCOE at $0.108/kWh, indicating a trade-off between cost and performance. Notably, HITEC Solar Salt demonstrated superior economic performance in key metrics, achieving the highest Net Present Value ($17,907,220) and Internal Rate of Return (7.64 %). In contrast, the 60 MW plant simulations revealed CALORIA HT 43 as the most favorable HTF, yielding the best annual AC energy output of 130,105,432 kWh-e and the lowest LCOE of $0.10/kWh, although it necessitated additional energy for freeze protection. Environmental impact analysis revealed that CSP plants using these HTFs emit significantly less CO₂ compared to fossil fuel-based plants, with annual emissions ranging from 1887 to 2602 tons for 30 MW and 60 MW plants, respectively. These findings suggest that while a 30 MW CSP plant may be suitable for HTFs like HITEC Solar Salt and Therminol fluids, larger capacity CSP plants (60 MW) are better suited for Benin City's meteorological conditions, with CALORIA HT 43 standing out in terms of performance, economic, and environmental metrics. This research contributes to the understanding of HTF selection in CSP systems, providing insights for optimizing renewable energy solutions in Nigeria and similar climates.