Electricity Grid

Extracted Attributes

• Type

  Interconnected network for electricity delivery

• Constraint

  Aging infrastructure capacity

• Economic Model

  Natural monopoly (most efficient for one operator)

• Vulnerabilities

  Malicious intrusion, cyber threats

• Operational Mode

  Synchronous (three-phase alternating current frequencies synchronized)

• Structural Types

  Microgrids, wide area synchronous grids, super grids

• Primary Components

  Power stations, electrical substations, electric power transmission lines, electric power distribution networks

• US Power Plants (2016 EIA)

  Over 7,300

• Key Operational Requirement

  Real-time balance of electricity supply and demand

• US Transmission Lines (DOE)

  More than 600,000 miles

• US Generating Capacity (DOE)

  More than 1 million megawatts

• US Electric Generating Units (DOE)

  More than 9,200

• US Electricity Customers (2016 EIA)

  145 million

• US High-Voltage Power Lines (2016 EIA)

  Nearly 160,000 miles

• Global Population Without Access (2017)

  Approximately 840 million people (ca. 11% of world population), mostly in Africa

• US Grid Interconnections (Lower 48 states)

  Three major interconnections

Timeline

• 1.2 billion people worldwide were without access to an electricity grid. (Source: Wikipedia)

  2010-01-01

• 1.4 billion people worldwide were not connected to an electricity grid. (Source: Wikipedia)

  2016-01-01

• Approximately 840 million people (ca. 11% of the World's population), mostly in Africa, had no access to grid electricity. (Source: Wikipedia)

  2017-01-01

Electrical grid

An electrical grid (or electricity network) is an interconnected network for electricity delivery from producers to consumers. Electrical grids consist of power stations, electrical substations to step voltage up or down, electric power transmission to carry power over long distances, and finally electric power distribution to customers. In that last step, voltage is stepped down again to the required service voltage. Power stations are typically built close to energy sources and far from densely populated areas. Electrical grids vary in size and can cover whole countries or continents. From small to large there are microgrids, wide area synchronous grids, and super grids. The combined transmission and distribution network is part of electricity delivery, known as the power grid. Grids are nearly always synchronous, meaning all distribution areas operate with three phase alternating current (AC) frequencies synchronized (so that voltage swings occur at almost the same time). This allows transmission of AC power throughout the area, connecting the electricity generators with consumers. Grids can enable more efficient electricity markets. Although electrical grids are widespread, as of 2016, 1.4 billion people worldwide were not connected to an electricity grid. As electrification increases, the number of people with access to grid electricity is growing. About 840 million people (mostly in Africa), which is ca. 11% of the World's population, had no access to grid electricity in 2017, down from 1.2 billion in 2010. Electrical grids can be prone to malicious intrusion or attack; thus, there is a need for electric grid security. Also as electric grids modernize and introduce computer technology, cyber threats start to become a security risk. Particular concerns relate to the more complex computer systems needed to manage grids.

Web Search Results

• U.S. Electricity Grid & Markets | US EPA

  The electricity grid is a complex machine in which electricity is generated at centralized power plants and decentralized units and is transported through a system of substations, transformers, transmission lines and distribution lines that deliver the product to its end user, the consumer. Since large amounts of electricity cannot be stored, it must be produced as it is used. [...] According to the U.S. Energy Information Administration (EIA), the U.S. power grid is made up of over 7,300 power plants, nearly 160,000 miles of high-voltage power lines, and millions of miles of low-voltage power lines and distribution transformers, connecting 145 million customers throughout the country (EIA, 2016). [...] Larger electricity networks are created through the interconnection of local grids, which are linked for commercial and reliability purposes. At the highest level, the network covering the lower 48 states is comprised of three major interconnections, functioning predominantly independently of one another with limited exchanges of power between them. Image 7: GPP North American Electric Power Grids

• The Grid: Electricity Transmission, Industry, and Markets

  The grid delivers electricity from generation points (e.g., power plants) to demand centers (e.g., homes and businesses). Supply and demand of electricity must be balanced in real-time to ensure system stability and reliability. A reliable grid is important for quality of life and can help prevent significant economic losses resulting from power disruptions, especially as electricity use becomes more widespread. In recent years the electricity grid has evolved from a centralized, one-way system [...] This is our Stanford University Understand Energy course lecture on the electricity grid. We strongly encourage you to watch the full lecture to understand the role of the grid in our energy system and how electricity industry and markets work. For a complete learning experience, we also encourage you to watch / read the Essential videos and readings we assign to our students before watching the lecture. [...] The electric grid is a natural monopoly because it is most efficient for one operator to provide the service. A competitive system would require each utility to build their own transmission and distribution lines, making electricity more expensive and our transmission system unwieldy. Imagine if our skyline looked like this!

• Grid Modernization and the Smart Grid - Department of Energy

  The electric grid is more than just generation and transmission infrastructure. It is an ecosystem of asset owners, manufacturers, service providers, and government officials at Federal, state, and local levels, all working together to run one of the most reliable electrical grids in the world. The Office of Electricity(OE) is working with its public and private partners to strengthen, transform, and improve energy infrastructure to ensure access to reliable, secure, and clean sources of [...] America’s economy, national security and even the health and safety of our citizens depend on the reliable delivery of electricity. The U.S. electric grid is an engineering marvel with more than 9,200 electric generating units having more than 1 million megawatts of generating capacity connected to more than 600,000 miles of transmission lines.

• Electrical grid - Wikipedia

  Grid energy storage (also called large-scale energy storage) is a collection of methods used for energy storage on a large scale within an electrical power grid "Grid (electricity)"). Electrical energy is stored during times when electricity is plentiful and inexpensive (especially from intermittent power sources such as renewable electricity from wind power, tidal power and solar power) or when demand is low, and later power is generated when demand is high, and electricity prices tend to be [...] Grids are designed to supply electricity to their customers at largely constant voltages. This has to be achieved with varying demand, variable reactive loads, and even nonlinear loads, with electricity provided by generators and distribution and transmission equipment that are not perfectly reliable. Often grids use tap changers on transformers near to the consumers to adjust the voltage and keep it within specification. ### Frequency [edit] Main article: Utility frequency [...] The smart grid is an enhancement of the 20th century electrical grid, using two-way communications and distributed so-called intelligent devices. Two-way flows of electricity and information could improve the delivery network. Research is mainly focused on three systems of a smart grid – the infrastructure system, the management system, and the protection system. Electronic power conditioning and control of the production and distribution of electricity are important aspects of the smart grid.

• Electricity Explained: How Electricity is Delivered to Consumers - EIA

  Electricity is generated at power plants and moves through a complex system, sometimes called the grid. The grid includes electricity substations, transformers, and power lines that connect electricity producers and consumers. Most local grids are interconnected to maintain reliability and for commercial purposes, forming larger, more dependable networks that helps suppliers consistently produce the right amount of electricity to meet demand. [...] The stability of the electricity grid requires electricity supply to constantly meet electricity demand, which in turn, requires numerous entities that operate different components of the grid to coordinate with each other. Local electricity grids are interconnected to form larger networks to maintain reliability and for commercial purposes. At the highest level, the U.S. power system in the Lower 48 states is made up of three main interconnections, which operate largely independently from each [...] In the United States, the entire electricity grid consists thousands of miles of high-voltage power lines and millions of miles of low-voltage power lines. This network of power lines connects thousands of power plants to hundreds of millions of electricity customers across the country. A flow diagram of power generation, transmission, and distribution from the power plant to residential houses. ## Electricity sources and types of providers