Energy Internet (EI) has been recently introduced as a new concept, which aims to evolve smart grids by integrating several energy forms into an extremely flexible and effective grid. In this paper, we have comprehensively analyzed Internet of Things (IoT) applications enabled for smart grids and smart environments, such as smart cities, smart homes, smart metering, and energy management infrastructures to investigate the development of the EI based IoT applications. These applications are promising key areas of the EI concept, since the IoT is considered one of the most important driving factors of the EI. Moreover, we discussed the challenges, open issues, and future research opportunities for the EI concept based on IoT applications and addressed some important research areas.presented in [12]. As a general definition, an EI system is composed of the combination of three important components that are energy systems, network systems, and ICT systems. In addition, these subsystems are connected to each other over energy routers, which comprise the main section of EI infrastructure. The energy routers are able to manage data and energy flow between these systems. The energy router idea is firstly proposed in [13], where they have two significant targets. While one of these targets is to perform dynamic scheduling of energy flows, the other is to enable communication with power devices. Different proposals related to system designs are reported in [14][15][16][17]. The use of communication technologies in EI is quite crucial to accomplish the goals of this vision. Therefore, ICTs are intensely adapted for enabling monitoring, controlling, and management processes in the EI concept. The wired and wireless communication technologies, such as ZigBee, WiMAX, cognitive radio, cellular communications, and the software-defined network (SDN), which are managed via the network system, are applied in the EI system to carry out monitoring, controlling, and management transactions in real-time [10]. One of the most recent communication technologies is the Internet of Things (IoT) [18,19] that has provided the development of numerous different communication protocols. The IoT can be exploited to ensure communication between devices employing dissimilar data types. Moreover, in order to present a communication platform in both machine-to-machine (M2M) and human-to-machine (H2M) environments, IoT technologies utilize several communication mediums, protocols, and layer architectures.A number of studies researching EI are available in the literature, which is only focused on the architecture of energy routers, techniques for system integration, SDNs, and big data analysis in the EI. To the best of our knowledge, any study surveying IoT applications in smart grids and smart environments has not been presented so far. We intend to present a comprehensive analysis of IoT applications in smart grids, smart cities, smart homes, smart metering, and EMSs to provide a further understanding of the EI concept. It is expected that these appl...
