New Hybrid CHP System Integrating Solar Energy and Exhaust Heat Thermochemical Synergistic Conversion with Dual-Source Energy Storage

For the efficient use of solar and fuels and to improve the supply-demand matching performance in combined heat and power (CHP) systems, this paper proposes a hybrid solar/methanol energy system integrating solar/exhaust thermochemical and thermal energy storage. The proposed system includes parabolic trough solar collectors (PTSC), a thermochemical reactor, an internal combustion engine (ICE), and hybrid storage of thermal and chemical energy, which uses solar energy and methanol fuel as input and outputs power and heat. With methanol thermochemical decomposition reaction, mid-and-low temperature solar heat and exhaust heat are upgraded to chemical energy for efficient power generation. The thermal energy storage (TES) stores surplus thermal energy, acting as a backup source to produce heat without emitting CO2. Due to the energy storage, time-varying solar energy can be used steadily and efficiently; considerable supply-demand mismatches can be avoided, and the operational flexibility is improved. Under the design condition, the overall energy efficiency, exergy efficiency, and net solar-to-electric efficiency achieve 72.09