Integration of energy systems for buildings and light industrial plants

This paper optimizes the design and operation of integrated distributed energy systems of large buildings and light industrial plants. The integration reduces greenhouse gas (GHG) emissions and the annual total cost (ATC) beyond the best possible from individual energy systems and there is a sharp optimum with respect to the size of the confectionary plant, which maximizes the reduction of GHG emissions and minimizes ATC. In contrast to previous studies, the design accounts for plant heating demands at different temperature levels and sets plant production volumes as decision variables. Optimal design, operation, and production schedule have been determined via a mixed-integer nonlinear programming model. Integrated energy systems of two entities (confectionary plant and residential building) have been compared to the non-integrated entities equipped with combined cooling, heating, and power systems. The lowest ATC (−8%) of the integrated system and the maximum GHG reductions (−8.3%) occur at slightly different sizes of the plant. Such reductions require simultaneous optimization of integrated design and operation of energy systems and relative sizes of the confectionary plant and the residential building.