# NFV-Enabled Efficient Renewable and Non-Renewable Energy Management: Requirements and Algorithms
## 2 Related Work
### ICT-Based Energy Management Systems  
In recent decades, the ICT infrastructure--especially IoT technology--has been identified as a key factor in the design and deployment of future energy systems because it enables the implementation of advanced energy monitoring, consumption, and management schemes [10]. Many studies have analyzed energy efficiency in IoT systems from different points of view, but the integration of IoT infrastructures in the operation of energy systems is still under development and it is a hot research topic at this time [7]. In this context, several research works have been proposed to encourage the use of ICT-based architectures, mechanisms, and strategies in energy systems. For instance, in [7], the authors survey the features, specifications, communications interfaces, and challenges in the design and deployment of IoT-based systems for energy management purposes in different application environments, such as smart homes, smart power grids, and smart cities. Given that IoT and DCs infrastructures have been identified as potential enablers for the deployment of DR programs, several studies have been proposed in this area [11]. For example, in [12], [PERSON] et al. proposed an IoT-based common information model and a communication framework to deploy a DR energy management system for industrial consumers. The proposal mostly analyzes the operation from the facility side (i.e., from the ECs-side), and the experimental results demonstrate that the interoperability between entities (ES and ECs) not only results in improvements in energy efficiency, but also a reduction in the energy cost on the consumer side. Meanwhile, in [13], the authors present a HEMS that includes sensors, local energy production (from photovoltaic panels), and a central hub for monitoring energy consumption and executing the DR strategies for controlling loads. The results show that the integration of IoT technologies and renewable energy in the housing sector optimizes energy performance and it is a sustainable practice for reducing carbon emissions. On the other hand, DCs infrastructures, due to characteristics, such as advanced monitoring capabilities, significant influence on the operation of power grids, constant growth, and highly automated computational resources, have been considered to be suitable candidates for implementing DR programs that can cover neighborhoods or entire cities [11]. Subsequently, DCs in DR schemes enabled by communications standards, such as the OpenADR Communication Specification [14] or the NFV technology, can act as an Energy Manager (EM) and coordinate the voluntary change in consumption patterns from ECs. This action is performed by executing management mechanisms (e.g., workload scheduling) to adapt consumption to generation over time [15]. Regarding NFV, this technology has been used in energy management for several specific applications. In power grids, for example, [PERSON] et al. [16], proposed an NFV-enabled virtual advanced metering infrastructure network to transmit energy-related information about power consumption and production, with the aim of improving energy management. In mobile communications, the use of NFV to improve energy management and achieve energy efficiency has also been explored. In [17], the authors use the GWATT tool [18] to estimate the energy savings for three NFV use cases: Virtualized Evolved Packet Core, Virtualized Customer Premises Equipment, and Virtualized Radio Access Network. Meanwhile, other works [19; 20] are focused on optimizing energy consumption and minimizing the energy footprint of the mobile network infrastructure (i.e., the transport networks and network functions) through the virtualization and management capabilities that are offered by NFV.