A review of uncertainty characterisation approaches for the optimal design of distributed energy systems

Energy models are valuable tools that are commonly employed for the optimal design of distributed energy systems (DES). However, the model-based design process of DES can be affected by uncertainty, which can lead to suboptimal design decisions and is introduced by aspects like the stochastic nature of renewables or the unknown future global energy and economy outlook. A critical first step of any effort to examine and incorporate uncertainty in the design process of DES includes the performance of a thorough uncertainty characterisation (UC). The UC task comprises the identification of the sources of uncertainty in the model's parameters and the assignment of a mathematical description to their uncertainty. The aim of this paper is to identify and categorise the most important uncertain parameters in typical DES design models and review the approaches used in the literature to represent their uncertainty. The uncertain aspects investigated pertain to the availability of renewable energy (wind and solar), the economic and environmental dimensions of energy carriers in a DES, the costs and technical characteristics of the technologies composing a DES, and, finally, the uncertain energy demands that a DES must satisfy. The analysis reveals the diversity and the varying complexity levels of the approaches used to characterise each parameter's uncertainty, as well as the specific parameters on which studies in the literature have mostly focused. Additionally, this review can serve to assist modellers who wish to introduce uncertainty considerations in their DES design model with the selection of appropriate UC approaches. Finally, in discussing the results of this review, directions for more effective UC in DES design are discussed, as well as suggestions for the integration of uncertainty in the design process of DES.