Techno-economic evaluation and optimized design of new trigeneration system for residential buildings

Improving energy efficiency and reducing CO2 emissions are main objectives of energy saving and emission reduction. However, residential buildings' daily operation not only consumes enormous energy, but emits relatively elevated CO2, which runs counter to energy saving and emission reduction. Consequently, it's urgent to acquire a more environmentally-friendly and efficient system for residential buildings. To solve this problem, a novel trigeneration system based on solid oxide fuel cell is proposed, integrating cooling, heating, electricity supply, and energy storage. Firstly, the system's mathematical model is established and the influence of key parameters on the system's performance is analyzed. Then, the genetic algorithm is utilized to optimize parameters of waste heat recovery system. Finally, the novel system is applied to satisfy energy demands of residential buildings, and five energy supply options are proposed to compare with the original option in terms of economy and environment. Numerical results show that among the five options, Option 3 has the best economy, with a payback period of 5.54 years and the total cost is 65.33% lower than the original option. Option 4 is more advantageous in reducing CO2 emissions, and its total CO2 emission in 15 years is 57.42% less than the original option.