Assessment of the Trilateral Flash Cycle potential for efficient solar energy conversion in Europe

Abstract

The potential of the Trilateral Flash Cycle (TFC) for the efficient conversion of solar energy to power in Europe is assessed in this work. A numerical analysis of a Solar-TFC thermal power unit is performed, by applying an in-house numerical model. Flat Plate Collectors (FPC) and Evacuated Tube Collectors (ETC) are modeled as solar heat sources. Particular focus is on the technological bottleneck of the TFC, i.e. two-phase expansion, by applying a novel two-phase expansion numerical model. Annual simulations are performed with the total efficiency of the Solar-TFC maximized at each time step. The annual total efficiency of the Solar-TFC, exergy efficiency, and thermal efficiency of the TFC can be as high as 5%, 5.3%, and 11%, respectively. ETCs increase the economic viability of the Solar-TFC, particularly as the annual electricity output increases. The Levelized Cost of Electricity (LCOE) of the modeled unit is estimated in the range of 0.25 and 0.75 €/kWh, which can be further reduced by increasing the collectors’ area. The Solar-TFC unit can reduce, on an annual basis, the CO2 emissions by 2.5–47 kg per m2 of solar collectors, with the carbon footprint reduction depending on the collectors’ efficiency and the installation location.

Keywords

• Solar-trilateral flash cycle
• Two-phase expansion
• Solar efficiency
• Thermal efficiency
• Exergy efficiency
• Economics