Comparative numerical assessment of power generation efficiency in two different scenarios: Solid oxide fuel cells vs. oxy-fuel technology for building solar heating and cooling systems

• Integrated solar PV, LAES, and either SOFC/oxy-fuel combustion for efficient building-scale energy use. • In a comparative scenario, SOFC is more cost-effective; oxy-fuel offers higher energy recovery (64% RTE). • Emission reduction is Achieved up to 70% lower CO₂ emissions than conventional systems This study addresses the challenges of peak electricity demand and renewable energy intermittency by proposing an innovative hybrid energy system that integrates solar photovoltaic (PV), Liquid Air Energy Storage (LAES), and LNG-based power generation. Two configurations are developed and compared using Aspen HYSYS one incorporating a Solid Oxide Fuel Cell (SOFC) and another employing an oxy-fuel combustion system with carbon capture. Comprehensive thermodynamic, exergy, and economic analyses are performed to determine the optimal configuration.Results indicate that the SOFC-based system (Scenario 1) achieves a round-trip efficiency (RTE) of 61.8%و storage efficiency of 75.2%, and system exergy efficiency of 71.4%, while the oxy-fuel system (Scenario 2) attains a slightly higher RTE of 64% with comparable exergy performance. Scenario 1 demonstrates better economic feasibility, whereas Scenario 2 provides improved heat recovery potential. The originality of this work lies in its solar-assisted, storage-integrated hybrid concept and the comparative assessment of two high-temperature systems, offering new insights for developing efficient, low-emission power solutions in regions with variable solar resources such as Iraq.