Abstract
The chapter describes the major components of the power grid. It then describes and explains the trends in the consumption and generation of electricity, with a particular focus on increasing the share of renewable energy sources. The concept of the smart grid is then described, including a discussion of the smart meter and the prosumer concept. The second part of the chapter is dedicated to electromobility. This section describes the main characteristics of electric vehicles and the trend of their diffusion, battery technologies, charging stations, smart charging, and the vehicle-to-grid concept.
TopPower Grid
The power grid, also known as the electrical grid, is a network of components that delivers electricity to consumers. First, it is important to understand a conventional power grid's basic elements and concepts. The main components of the power grid are:
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Generating Plants, also known as power plants or stations, produce electricity using either combustible fuels such as coal, natural gas, and biomass or noncombustible energy sources such as wind, solar energy, and nuclear fuels. Today, they are usually located near energy sources and far from densely populated areas. The other parts of the power grid are therefore critical to delivering electricity from the generation source to the consumer.
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Electrical Substations to adjust the voltage to the required level. Electric power normally flows through several substations with different voltage levels between the generating plants and the final consumer. Components called transformers are used to transfer electrical energy from one circuit to another (with different voltage levels).
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Electric Power Transmission Network is used to transmit electricity over long distances. The higher the voltage of a transmission line, the more power it can carry. Transmission networks are used to transmit electricity from large production plants to areas of concentrated consumption, where they are connected to distribution networks at substations or even directly to the largest industrial consumers (e.g. ironworks). The transmission network also serves as a link between the national power grids of different countries. The transmission network consists of overhead lines, and less frequently, cable lines and distribution or substations. Since transmission networks transmit large amounts of power, they are high- and medium-voltage networks. There are no clear and universally accepted boundaries, however, transmission networks in principle operate above 30 kV, typically even higher (e.g. 110 kV, 220 kV, and 400 kV) (International Electrotechnical Commission, 2022).
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Electric Power Distribution Network is used to deliver electricity to individual customers. The step-down transformer is used to reduce the voltage so that the electricity can reach the end customers through the distribution lines. Therefore, it consists of substations and transmission lines of various lower voltage classes (normally below 30 kV) to distribute electricity to end users (Kaplan, 2009 & International Electrotechnical Commission, 2022).
Key Terms in this Chapter
Electric Vehicles: Electric vehicles (EVs) are vehicles that use electricity for their propulsion, using batteries and electric motors. Electric vehicles can be pure electric vehicles, also known as battery electric vehicles (BEVs), which draw all their energy from the power grid or so-called vehicles plug-in hybrid electric vehicles (PHEVs) which also use an alternative energy source to assist electric powertrain.
Electromobility: Electromobility refers to the concept of using electric vehicles and other means of transport which use electric power for their propulsion to transport people and goods.
Prosumer: Prosumer refers to a type of active energy consumer who consumes electricity from the power grid and also produces it for his own consumption or for sale in the grid. The term “prosumer” is a combination of the two words “producer” and “consumer”.
Power Grid: The power grid, also known as the electrical grid, is a network of components which delivers electricity to consumers. The main components of the power grid are: generating plants, electrical substations, an electric power transmission network and an electric power distribution network.
Smart Charging: Smart charging refers to an advanced electric vehicle charging system which aims to manage the charging process in an intelligent way to achieve given objectives. Compared to uncoordinated charging, where vehicles start charging as soon as they are plugged, smart charging, also known as coordinated charging or directed charging, adjusts the time and power of charging. For example, such a system can optimise charging costs in a way that a vehicle is charged when the price and demand of electricity are the lowest.
Smart Grid: Smart grid refers to the power grid that uses advanced information and communication technologies that enable bidirectional communication in the grid, monitoring and intelligent management of the grid. The smart grid aims to better connect all components of the power grid and ensure a more stable and secure supply of electricity.
Vehicle-to-Grid: Vehicle-to-Grid (V2G): refers to the concept of electric vehicle charging where the vehicle draws electricity from the grid, stores it and returns electricity into the grid. Vehicle-to-Grid is an advanced form of electric vehicle smart (coordinated) charging with bidirectional energy flow capability. By discharging electricity from the battery back into the grid, electric vehicle contribution to the grid ancillary services.