Design Under Uncertainty of a Multi-Energy System with Seasonal Storage : On the Importance of the Operation Strategy in the Design Procedure

This paper focuses on the integrated design and operation under uncertainty of a multi-energy system with seasonal storage: the future energy demand, the production, and the electricity tariff are not perfectly known while sizing and operating the system. Solving such complex problems is most of the time intractable, so simplifications are inevitable for the purpose of optimization: the integrated design problem is usually solved on a finite set of scenarios with an operation strategy that might be different from the one finally used in real life. The main objective of this paper is to challenge this latter approximation by providing a comprehensive comparison of different design and operation strategies under uncertainty. To this end, a stochastic framework is introduced where the design and the assessment phases are divided into two distinct parts. First, the equipment sizes are obtained by solving a two-stage model using both: 1) a mathematical programming approach, and 2) a metaheuristic method with different nested operation strategies. Then, the sizing values are evaluated on a common out-of-sample simulator with realistic operation policies. This work reinforces the importance of the operation strategy in the design procedure as it can lead to misleading results