a two-stage optimization model for risk-based off-grid zero-energy building planning

Zero-energy buildings (zebs) are a design option developed to meet the environmental benefits and long-term cost savings for both the governments and customers. however, geographical and climate situations like being remote, difficult crossing and renewable-suited have attracted the attentions to off-grid zebs. off-grid zeb is an effective solution for the customers living in such regions, which denotes the concept of supplying building’s demand from a standalone energy system independent of urban electricity infrastructure. besides, envelope thermal insulating as the passive design plays a key role in the energy efficiency enhancement of buildings. this paper presents a bi-level optimization model of a risk-based off-grid zeb planning in hot climate regions, which consists of sizing the standalone energy system and designing the required thermal insulation. the upper-level problem seeks to find the cost-optimal capacities of the energy resources and determine the insulation design parameters. the expected annual operation cost is extracted from the lower-level problem that is defined within a scheduling model and ensures the feasibility of the sizing problem in meeting the annual electric demand. the robust approach as the risk management tool is employed to mitigate the inherent uncertainty associated with the building demand. furthermore, the bi-level problem is solved through a hybrid algorithm, composed of numerical metaheuristic and mathematical programming method. moreover, an industrial campus in kish island is selected as the simulation case study to validate the proposed approach in creating an off-grid energy efficient system.