Resilience (power system)

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Power resilience refers to a company's ability to adapt to power outages. Frequent outages have forced businesses to take into account the "cost of not having access to power" in addition to the traditional "cost of power". [1] Climate-related issues have intensified the attention on energy sustainability and resilience. In the United States, electric utility firms have registered over 2500 significant power outages since 2002, with almost half of them (specifically 1172) attributed to weather events, including storms, hurricanes, and other unspecified severe weather occurrences. [2] These incidents often lead to significant economic losses. [3]

Contents

The Committee on Enhancing the Resilience of the Nation's Electric Power Transmission and Distribution System has developed strategies that seek to reduce the impact of large-scale, long-duration outages. Resilience is not just about preventing these outages from happening, but also limiting their scope and impact, restoring power quickly, and preparing for future events. [4]

Some parts of the United States still rely on regulated, vertically integrated utilities, while others have adopted competitive markets. Efforts to improve resilience must take into account this institutional and policy heterogeneity. [4]

The use of automation at the high-voltage level can improve grid reliability, but also introduces cybersecurity vulnerabilities. These "smart grids" use improved sensing, communication, automation technologies, and advanced metering infrastructure. [4]

Distributed energy resources are rapidly growing in some states, but most U.S. customers will continue to depend on the large-scale, interconnected, and hierarchically structured electric grid. Therefore, strategies to enhance electric power resilience must consider a diverse set of technical and institutional arrangements and a wide variety of hazards. There is no single solution that fits all situations when it comes to avoiding, planning for, coping with, and recovering from major outages. [4]

Definition

According to the US Department of Homeland Security (DHS), resilience is defined as "the ability to adapt to changing conditions and withstand and rapidly recover from disruption due to emergencies". [5]

Causes

Power outages can be caused by various events, not just weather conditions. These events can be classified as either "low-frequency high-impact" or "high-frequency low-impact." Dealing with low-frequency high-impact events, also known as "large area long duration" events, is particularly challenging due to the significant devastation they cause over a vast area for an extended period. These events are generally unpredictable and occur unexpectedly, but advances in weather and disaster forecasting technology can offer some warning time to prepare for certain situations. [4] Power outages can be caused by a wide range of factors, including natural disasters, cyberattacks, equipment failure, human error, and political instability. The impact of a disruptive event on the power system infrastructure can be significant, depending on the severity of the event and the condition of the infrastructure. For example, a severe storm can knock out power to a large geographical area, while a cyberattack on the communication systems can disrupt the entire power grid. Additionally, the interdependence of different infrastructures, such as energy, transportation, and communication, can exacerbate the impact of a disruptive event. Finally, the spatial and temporal impacts of a disruptive event can affect how quickly power can be restored, as well as the level of damage to the infrastructure. Overall, managing the risk of power outages requires a comprehensive approach that considers a range of potential disruptive events and their potential impact on the power system infrastructure.

Importance

Regardless of the reasons, one growing concern is that power outages result in economic losses and hardship for people who have become increasingly reliant on electricity for even basic comforts. So it is essential that electrical power systems (EPSs) around the world are resilient. A resilient EPS should ensure uninterrupted power supply, even in the face of minor faults and major disruptive events. It should be robust enough to be reliable and have the ability to predict and prepare for potential outages. Additionally, a resilient EPS should have a mechanism to quickly recover and restore power to critical establishments. However, while power system reliability is well-defined and has established metrics in the electricity sector, resiliency is often confused with reliability, despite some similarities. [3]

According to the findings of National Academies report, the electric grid's smooth operation, which is organized in a hierarchical structure and tightly interconnected on a large scale, will remain crucial for ensuring dependable electric service to the majority of consumers over the next two decades. [4] Power disruptions are problematic for both consumers and the electric system itself. These disruptions are typically caused by physical damage to local parts of the system, such as lightning strikes, falling trees, or equipment failure. The majority of outages affecting customers in the United States are caused by events that occur in the distribution system, while larger storms, natural phenomena, and operator errors can cause outages across the high-voltage system. A variety of events, such as hurricanes, ice storms, droughts, earthquakes, wildfires, and vandalism, can lead to outages. When power goes out, life becomes more challenging, especially in terms of communication, business operations, and traffic control. Brief outages are usually manageable, but longer and wider outages result in greater costs and inconveniences. Critical services like medical care, emergency services, and communications can be disrupted, leading to potential loss of life. This report focuses on building a resilient electric system that minimizes adverse impacts of large outages, particularly blackouts that last several days or longer and extend over multiple areas or states, which are particularly problematic for a modern economy that depends on reliable electric supply. [6]

Resilience vs reliability

Despite the efforts of utilities to prevent and mitigate large-scale power outages, they still occur and cannot be eliminated due to the numerous potential sources of disruption to the power system. It is somewhat surprising that such outages are not more frequent, considering the magnitude of the system and the potential for problems. However, the planners and operators of the system have made great efforts over many years to ensure that the electric system is engineered and operated with a high level of reliability. In recent times, there has been an increased emphasis on resilience as well. The North American Electric Reliability Corporation (NERC), which is responsible for developing reliability standards for the bulk power system, defines reliability in terms of two fundamental concepts. [7]

  1. Adequacy: Adequacy refers to the capability of the electricity system to meet the overall electricity demand and energy needs of end-users consistently, considering both planned and unexpected outages of system components that are reasonably anticipated.
  2. Operating reliability: The capability of the overall electrical power system to endure unexpected disruptions, like electrical faults or unforeseen component failures due to credible emergencies, without experiencing unmanaged, widespread power outages or harm to machinery.

The system's reliability standards vary in practice, and while the bulk power system maintains a relatively high level of reliability throughout the United States, it cannot be made completely faultless due to its complexity as a "cyber-physical system." To ensure adequacy of electricity generation capability, a one-day-in-ten-years loss of load standard is commonly used, which means that the generation reserves must be sufficient to prevent voluntary load shedding due to inadequate supply from occurring more than once every ten years. However, with millions of intricate physical, communications, computational, and networked components and systems, the system is inherently complex and cannot attain perfect reliability.

Resilience and reliability are two different concepts. Resilience, as defined by the Random House Dictionary of the English Language , refers to the ability to return to the original state after being stretched, compressed, or bent. Moreover, resilience involves recovering from adversity, illness, depression, or other similar situations. It also encompasses the ability to rebound and cope with outages effectively by reducing their impacts, regrouping quickly and efficiently after the event ends, and learning to handle future events better. [8]

See also

Related Research Articles

<span class="mw-page-title-main">North American Electric Reliability Corporation</span> Non profit Electric Reliability Organization

The North American Electric Reliability Corporation (NERC) is a nonprofit corporation based in Atlanta, Georgia, and formed on March 28, 2006, as the successor to the North American Electric Reliability Council. The original NERC was formed on June 1, 1968, by the electric utility industry to promote the reliability and adequacy of bulk power transmission in the electric utility systems of North America. NERC's mission states that it "is to assure the effective and efficient reduction of risks to the reliability and security of the grid".

<span class="mw-page-title-main">Geomagnetic storm</span> Disturbance of the Earths magnetosphere

A geomagnetic storm, also known as a magnetic storm, is temporary disturbance of the Earth's magnetosphere caused by a solar wind shock wave.

<span class="mw-page-title-main">Power outage</span> Loss of electric power to an area

A power outage is the loss of the electrical power network supply to an end user.

<span class="mw-page-title-main">Rolling blackout</span> Intentionally engineered electrical power shutdown

A rolling blackout, also referred to as rota or rotational load shedding, rota disconnection, feeder rotation, or a rotating outage, is an intentionally engineered electrical power shutdown in which electricity delivery is stopped for non-overlapping periods of time over different parts of the distribution region. Rolling blackouts are a last-resort measure used by an electric utility company to avoid a total blackout of the power system.

A microgrid is a local electrical grid with defined electrical boundaries, acting as a single and controllable entity. It is able to operate in grid-connected and in island mode. A 'stand-alone microgrid' or 'isolated microgrid' only operates off-the-grid and cannot be connected to a wider electric power system.

<span class="mw-page-title-main">Transmission system operator</span> Energy transporter

A transmission system operator (TSO) is an entity entrusted with transporting energy in the form of natural gas or electrical power on a national or regional level, using fixed infrastructure. The term is defined by the European Commission. The certification procedure for transmission system operators is listed in Article 10 of the Electricity and Gas Directives of 2009.

High availability (HA) is a characteristic of a system that aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period.

<span class="mw-page-title-main">Texas Interconnection</span> Power grid providing power to most of Texas

The Texas Interconnection is an alternating current (AC) power grid – a wide area synchronous grid – that covers most of the state of Texas. The grid is managed by the Electric Reliability Council of Texas (ERCOT).

Infrastructure security is the security provided to protect infrastructure, especially critical infrastructure, such as airports, highways rail transport, hospitals, bridges, transport hubs, network communications, media, the electricity grid, dams, power plants, seaports, oil refineries, liquefied natural gas terminals and water systems. Infrastructure security seeks to limit vulnerability of these structures and systems to sabotage, terrorism, and contamination.

<span class="mw-page-title-main">Smart grid</span> Type of electrical grid

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.

<span class="mw-page-title-main">Electrical grid</span> Interconnected network for delivering electricity from suppliers to consumers

An electrical grid 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 long distances, and lastly electric power distribution to individual customers, where voltage is stepped down again to the required service voltage(s). 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.

A resilient control system is one that maintains state awareness and an accepted level of operational normalcy in response to disturbances, including threats of an unexpected and malicious nature".

Smart grid policy in the United States refers to legislation and other governmental orders influencing the development of smart grids in the United States.

A Distribution Transformer Monitor (DTM) is a specialized hardware device that collects and measures information relative to electricity passing into and through a distribution transformer. The DTM is typically retrofitted onto pole top and pad mount transformers. A pole top or pad mount transformer commonly powers anywhere from 5-8 homes in the US and is the last voltage transition in stepping down voltage before it gets to the home or business. The conventional placement of Distributed Temperature Monitoring (DTM) devices is typically observed at the terminals of transformers. However, there are instances where these devices are directly affixed to the secondary power lines. DTM apparatus commonly comprises precision-centric sensors, either of the non-piercing or piercing variety, in addition to communication modules integrated onboard for seamless data transmission. Adequate provisions for power supply are also incorporated within the DTM setup. The captured data from the DTM unit is relayed to a central data collection engine and/or the established Supervisory Control and Data Acquisition (SCADA) / Meter Data Management (MDM) system, where pertinent information pertaining to the transformer is stored and made accessible to users. Often, analytical platforms come into play to decipher the data gleaned and reported by the DTM, thereby enhancing the comprehension of the acquired information.

Passive survivability refers to a building's ability to maintain critical life-support conditions in the event of extended loss of power, heating fuel, or water. This idea proposes that designers should incorporate ways for a building to continue sheltering inhabitants for an extended period of time during and after a disaster situation, whether it be a storm that causes a power outage, a drought which limits water supply, or any other possible event.

Community resilience is the sustained ability of a community to use available resources to respond to, withstand, and recover from adverse situations. This allows for the adaptation and growth of a community after disaster strikes. Communities that are resilient are able to minimize any disaster, making the return to normal life as effortless as possible. By implementing a community resilience plan, a community can come together and overcome any disaster, while rebuilding physically and economically.

Electric grid security in the US refer to the activities that utilities, regulators, and other stakeholders play in securing the national electricity grid. The American electrical grid is going through one of the largest changes in its history, which is the move to smart grid technology. The smart grid allows energy customers and energy providers to more efficiently manage and generate electricity. Similar to other new technologies, the smart grid also introduces new concerns about security.

<span class="mw-page-title-main">2021 Texas power crisis</span> Mass power outages triggered by snow and ice storms

In February 2021, the state of Texas suffered a major power crisis, which came about during three severe winter storms sweeping across the United States on February 10–11, 13–17, and 15–20. The storms triggered the worst energy infrastructure failure in Texas state history, leading to shortages of water, food, and heat. More than 4.5 million homes and businesses were left without power, some for several days. At least 246 people were killed directly or indirectly, with some estimates as high as 702 killed as a result of the crisis.

Resource adequacy in the field of electric power is the ability of the electric grid to satisfy the end-user power demand at any time. RA is a component of the electrical grid reliability. For example, sufficient unused generation capacity shall be available to the electrical grid at any time to accommodate major equipment failures and drops in variable renewable energy sources. The adequacy standard should satisfy the chosen reliability index, typically the loss of load expectation (LOLE) of 1 day in 10 years.

The power system reliability is the probability of a normal operation of the electrical grid at a given time. Reliability indices characterize the ability of the electrical system to supply customers with electricity as needed by measuring the frequency, duration, and scale of supply interruptions. Traditionally two interdependent components of the power system reliability are considered:

References

  1. ↑ Frank, T. (2019). E&E News reporter. https://www.eenews.net/stories/1061245945.
  2. ↑ Hussain, A., & Pande, P. (2020). https://www.bloomenergy.com/blog/2020-predictionstop-energy-trends-were-anticipating-this-year.
  3. 1 2 "1st Edition". Electric Power Systems Resiliency. 2022-07-14. Retrieved 2023-03-27.
  4. 1 2 3 4 5 6 Enhancing the Resilience of the Nation's Electricity System. Washington, D.C.: National Academies Press. 2017-09-25. doi:10.17226/24836. ISBN   978-0-309-46307-2.
  5. ↑ House, W. (2013). Critical infrastructure security and resilience. Vol. 12. Presidential Policy Directive/PPD–21. US: White House. https://www.govinfo.gov/content/pkg/PPP2013-book1/pdf/PPP-2013-book1-doc-pg106.pdf. (Accessed 5 January 2022).
  6. ↑ Enhancing the Resilience of the Nations Electricity System, pp. 8–9
  7. ↑ Enhancing the Resilience of the Nations Electricity System, p. 9
  8. ↑ Enhancing the Resilience of the Nations Electricity System, p. 10
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