Innovative Power Generation with SOFC-GT And Stirling Engine Integration

This study explores the development and thermodynamic performance evaluation of an innovative hybrid energy system that combines Solid Oxide Fuel Cells (SOFC), a Gas Turbine (GT), and a Stirling Engine (SE) to improve energy efficiency and recover waste heat effectively. Two configurations are analyzed in detail: the first integrates SOFC with a gas turbine cycle only, representing a more conventional hybrid system; the second configuration incorporates a Stirling engine downstream toutilize the high-temperature exhaust gases for additional power generation and improved thermal management. Thermodynamic and exergy analyses were carried out using realistic system parameters to assess the performance of both configurations under varying operating pressures and temperatures. The results clearly show that integrating the Stirling engine increases both electrical and exergy efficiencies by approximately 3–5 percentage points, particularly at optimal operating pressures of 8–9 bar. Moreover, raising the SOFC operating temperature up to 850°C significantly boosts overall system performance. Under these high-temperature conditions, the Stirling engine contributes an additional 18– 50 kW of power output, demonstrating its strong capability to recover residual thermal energy that would otherwise be wasted. The inclusion of the Stirling engine not only enhances thermal utilization and boosts net power output but also reduces fuel consumption and improves the environmental sustainability of the system by lowering greenhouse gas emissions. Keywords: Hybrid Energy System, Stirling Engine (SE), Thermodynamic Analysis, Waste Heat Recovery.