The energy hub: An extensive survey on the state-of-the-art

Today's world energy-related challenges, ranging from anthropogenic climate change to continuous growth of demand for different energy forms, have enforced planners of energy systems (ESs) to concentrate on more optimal and eco-friendly operation and/or expansion planning methodologies. In this context, increased interdependencies of gas, heat and electricity ESs have recently encouraged the planners to design operation and/or expiation strategies in an integrated manner in favor of a new concept, the so-called Energy Hub (EH). Although this concept has been employed so far in a multitude of studies, but its real nature, advantages, difficulties, importance or inevitability aspect, and eventually, its application areas in power industries have remained as open questions from various viewpoints. On the other hand, the difference in the planners' perceptions of the EH concept has caused emerging various definition and models for this. At this point, it is worth reviewing the frameworks proposed for planning the ESs based on the EH approach, while understanding the application areas of the EH, its components, the nature behind presented definitions, and the hierarchy of events/factors drawing the planners attention to this approach, can help to find the answers of the questions. In doing so, this paper presents a state-of-the-art review of existing research works focusing on the operation and/or expansion planning problems of ESs in the context of EH. Reviewing results and findings can be helpful for both researchers new to this field of study by extraction of the distinguishing borders between underlying concepts and presenting an in-depth review on the latest studies, and experts in this research field by summarizing the details of a wide range of relevant works and extracting research gaps.