Economic and environmental assessment of a CO₂ solar-powered plant with packed-bed thermal energy storage

Abstract

Investigating supercritical natural fluids for efficient and clean energy production has become a trending research topic due to their technical and environmental advantages. However, on account of the supercritical operational conditions, using specially-developed components increases manufacturing prices, especially when dealing with solar-powered plants assisted by thermal energy storage (TES) systems. This paper assesses the economic and environmental trends of an integrated supercritical carbon dioxide (s-CO₂) solar-powered plant. The system is composed of a packed-bed TES system, a solar field, and a power block while considering conventional backup heating. Transient year-around numerical simulations explore several operational conditions relying on detailed cost and typical meteorological year (TMY) data. Also, the modeling accounts for the system's environmental sustainability through a penalization cost regarding CO₂ emissions due to auxiliary heating. With parametric analyses, the study assesses the compromise solutions minimizing the levelized cost of energy (LCOE). The results revealed the possible feasibility of the integrated system using such a TES technology for s-CO₂ and evidenced several venues for further examination. In the end, a sensitivity analysis investigates the influence of the specific costs and TMY data on the LCOE.