Life cycle techno-economic-environmental optimization for capacity design and operation strategy of grid-connected building distributed multi-energy system

Distributed multi-energy systems (DMS) have received increasing attention. Many studies have optimized the capacity and operation strategies of DMS based on multiple objectives, but these studies must discuss the weights of different objectives and have not considered the internal coupling between different objectives. Besides, existing studies have not considered the changes in the actual value of environmental impacts. To address these shortcomings, this paper constructs a technology-economic-environmental optimization model by mixed-integer linear programming. Based on life-cycle assessment, the model quantifies the value of system life-cycle environmental impacts by introducing carbon price. The case results show that the proposed optimization model can reduce the total cost by 28.83 % and the life cycle environmental cost by 3.39 % compared to the traditional model. To reduce the strain on the grid, a new operation pattern (The grid provides fixed electricity to the system throughout the year.) is proposed. The electricity interaction of the system with the grid under the new operation pattern is more than 70 % lower than the system without electricity purchased quantity constraint. Sensitivity analysis shows the total system cost is more sensitive to natural gas and electricity price than carbon price. But carbon price volatility helps reduce system carbon emissions.