Energy management for user’s thermal and power needs: A survey <s> A.7. Virtual power plants <s> Three dominant factors are impacting future electric systems of the world: governmental policies at both federal and state levels, customer efficiency needs, and new intelligent computer software and hardware technologies. In addition, environmental concerns are driving the entire energy system to efficiency, conservation, and renewable sources of electricity. Customers are becoming more proactive and are being empowered to engage in energy consumption decisions affecting their day-to-day lives. At the same time, energy needs are continually expanding. For example, consumer participation will soon include extensive use of electric vehicles (both cars and trucks), remote control of in-home appliances to promote energy conservation, ownership of distributed generation from ever more renewable energy sources, and management of electricity storage to locally match supply to demand. The availability of new technologies such as distributed sensors, two-way secure communication, advanced software for data management, and intelligent and autonomous controllers has opened up new opportunities for changing the energy system. For instance, while networking technologies and systems have been greatly enhanced, the Smart Grid faces challenges in terms of reliability and security in both wired and wireless communication environments. In particular, smart home appliances represent a major part of the Smart Grid vision, which aims at increasing energy efficiency. To achieve this goal, home appliances need to communicate with entities and players in other Smart Grid domains via home area networks. Therefore, the electric system of the future will address all these needs and concerns by using new advanced technologies to create a smarter, more efficient and sustainable grid. Although many different definitions have been proposed for the Smart Grid, in most cases, the users have chosen narrowly focused definitions related to their specific applications and local needs. The main objective of this special issue is to report on some, if not all, of the technical challenges posed by this conversion. While acknowledging its limited coverage, this special issue offers a range of valuable contributions. For the benefit of readers before beginning your excursion, we first provide a description of the current conventional electric energy system. We then identify the key areas that must change in order to provide the intelligence and control necessary to convert to the safe, secure, and efficient Smart Grid of the future. <s> BIB001 </s> Energy management for user’s thermal and power needs: A survey <s> A.7. Virtual power plants <s> Smart grids are often analyzed using a top-down approach, i.e., starting from communication and control technologies evolution, to then focus on their effects on active and passive users, in terms of new services, higher efficiency and quality of supply. However, with their bottom-up approach, virtual power plants (VPP) are very promising instruments for promoting an effective integration of distributed generation (DG) and energy storage devices as well as valid means for enabling consumers to respond to load management signals, when operated under the supervision of a scheduling coordinator. These aggregation factors can be very profitable for the distributed energy resources (DERs) economy and for the energy network itself. This paper presents a new algorithm to optimize the day-ahead thermal and electrical scheduling of a large scale VPP (LSVPP) which contains: a) many small-scale producers and consumers (“prosumers”) distributed over a large territory and b) energy storage and cogeneration processes. The algorithm also takes into account the actual location of each DER in the public network and their specific capability. Thermal and electrical generator models, load and storage devices are very detailed and flexible, as are the rates and incentives framework. Several novelties, with respect to the previous literature, are proposed. Case study results are also described and discussed. <s> BIB002 </s> Energy management for user’s thermal and power needs: A survey <s> A.7. Virtual power plants <s> Multiple energy carrier systems stem from the need to evolve traditional electricity, gas and other energy systems to more efficient, integrated energy systems. An approach is presented, for controlling multiple energy carriers, including electricity (AC or DC), heat, natural gas and hydrogen, with the objective to minimise the overall cost and/or emissions, while adhering to technical and commercial constraints, such as network limits and market contracts. The technique of multi-agent systems (MAS) was used. The benefits of this approach are discussed and include a reduction of more than 50% in the balancing costs of a potential deviation. An implementation of this methodology is also presented. In order to validate the operation of the developed system, a number of experiments were performed using both software and hardware. The results validated the efficient operation of the developed system, proving its ability to optimise the operation of multiple energy carrier inputs within the context of an energy hub, using a hierarchical multi-agent system control structure. <s> BIB003
A VPP is defined by the FENIX project (FENIX project, 2007) as an entity that ''aggregates the capacity of many diverse DERs, it creates a single operating profile from a composite of the parameters characterizing each DERs and can incorporate the impact of the network on aggregate DERs output. A VPP is a flexible representation of a portfolio of DERs that can be used to make contract in the wholesale market and to offer services to the system operators''. The concept of VPP has been traditionally used in the industrial sector, giving small power plants owners the possibility to ''collectively'' access and trade on the energy market BIB002 . However, the concept can be extended to residential users, as they can offer flexibility in return for profit. In  , the VPP model is used to describe residential and tertiary users, which are referred to as Sustainable Energy Microsystem and include electric mobility, electric vehicles, small-scale RES plants, CCHP generators, and the heating and cooling system. In BIB003 , different aggregation levels are considered within a hierarchical structure. A group of DERs and 20 residential loads are represented as en energy hub, with input and output ports. The interaction between the hub and the distribution grids is modeled as a microgrid, whereas the trades with the energy markets are defined by a VPP. A.8. Smart grid ''Smart Grid'' is the broadest concept that encompass all previously defined levels and refers to the new vision of the electricity grid, from transmission to distribution. The main goal is to build on the available infrastructure to increase the efficiency and reliability of the system, the security of supply, the use of renewable sources, and the operational flexibility and sustainability exploiting the increasing availability of information and communication technologies BIB001 . The key element to achieve such an electric grid is a secure exchange of information to promote the coordination and interoperability among all energy stakeholders: from energy utilities, to buildings, to smart appliances.