Evaluating the cost of energy flexibility strategies to design sustainable building clusters: Modelling and multi-domain analysis

The increasing complexity of urban distributed energy systems demands effective strategies to tackle design and operational challenges. This study presents a framework for evaluating energy flexibility strategies in building clusters, aiming to minimize costs across various domains. By analysing thermostat adjustments and load adaptations, the study assesses the economic and non-economic costs, namely energy expenses and variation in occupant thermal comfort. A simulation platform has been developed to carry out multi-domain analyses, aiming to enhance the utilization of renewable energy and manage grid power demand. The model integrates detailed building energy models with a district grid model in co-simulation mode, augmenting the capabilities of current energy models in capturing multi-domain aspects of the design, such as occupants’ response to flexibility events. The model integrates distributed renewable energy sources and energy storage systems aggregated with different building typologies forming energy communities. Proof-of-concept simulations are conducted, showcasing the multi-faceted costs of implementing energy communities, including photovoltaic, battery energy storage, and a building cluster composed of residential, office, and service buildings. Sensitivity analysis evaluates the impact of flexibility strategies on renewable energy consumption and occupant comfort. The results of the study help to understand and quantify the impact of measures encouraging the engagement of citizens in such communities' response programs and inform the design and operation of such strategies. It is demonstrated that for the case study, the use of BESS in demand management raises the utilization of renewable energy by up to 25 %, while load adaptations lead to an 8 % increase in renewable energy consumption. The maximum variation in thermal comfort sensation is achieved adapting setpoint at lower aggregate load thresholds. Compared to previous district grid models, this framework provides a more comprehensive evaluation by quantifying the specific effects on renewable energy use and occupant comfort through detailed dynamic building simulation.