Multi-objective approach to economic and environmental optimal operations of cogeneration for building energy management system

This paper proposes economic and environmental optimal operations of combined heat and power (CHP) systems for a building energy management system (BEMS). BEMS consists of a CHP system, an auxiliary boiler, an absorption chiller, and power grids. The problem concerns with multiobjective cost functions, including total operating cost, the minimum total carbon dioxide (CO₂) emission, and optimal energy flows. Then, we show that it can be formulated as a linear program which can be efficiently solved. In a case study, load profiles are taken from a large shopping mall building. Moreover, the simulation is extended to determine the impact of natural gas prices onto the total operating cost. The numerical results demonstrate that economic and environmental optimal operations for BEMS can reduce total energy cost of the building but slightly increase CO₂ emissions. Moreover, the fluctuation in fuel prices may cause risks in the investment of such a BEMS.