Reducing carbon emissions and energy costs in multi-building facilities: A Co-optimisation approach

Commercial buildings remain one of the most significant consumers of energy. As such, any sustainable pathway to a zero-emissions future will need to pay close attention to emissions reduction in commercial buildings. An interesting category of commercial buildings is the multi-building commercial facility with different buildings collocated within a defined geographical area, serving different purposes and containing varying equipment types. While most existing facility management approaches focus on minimising energy costs and emissions at the level of each building, this work considers a different perspective where energy and emissions are co-optimised across all buildings within the facility. Illustrative case studies based on a multi-building facility consisting of individual buildings adapted from the United States Department of Energy's (DOE) Commercial Reference Buildings database are considered. Different diurnal and seasonal variations in building usage are also considered. Simulations are run using a Python-based commercial building simulation toolbox. Results indicate that the co-optimisation approach can indeed provide superlinear emissions reductions and energy cost savings while satisfying predefined comfort limits compared to when each building is separately optimised.