Techno-Economic Analysis of a Novel CSP and sCO2-Based System for Waste Heat Recovery in Gas Turbine Power Plants

Waste heat recovery is an underutilized strategy for reducing emissions and mitigating climate change. High-temperature exhaust from gas turbines (GTs) is often not utilized, leading to both energy losses and emissions. This study proposes a novel WHR system that integrates a supercritical carbon dioxide (sCO2) Brayton cycle with a concentrated solar power (CSP) component, including thermal energy storage, for GT heat recovery. The WHR system boosts overall efficiency, sustainability, and economic performance by harnessing GT exhaust and solar-derived heat. One application of GTs is providing off-grid electricity to remote mining operations. A comprehensive techno-economic simulation model is developed, and a case study for a mining site in Western Australia is presented. The results show that the proposed CSP–sCO2 WHR system can provide an additional 56,028.78 MWh/year at a levelized cost of electricity (LCOE) of $0.0597/kWh, substantially increasing the output of the GT plant while reducing emissions and costs. Compared to a standalone CSP–Rankine plant, the proposed system halves capital expenditures, cutting LCOE by $0.0246/kWh. The proposed WHR system highlights the potential for reducing emissions and fuel costs in GTs, while the comparison with CSP–Rankine demonstrates how integrating CSP with waste heat can help achieve CSP LCOE targets.