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Rolling blackout

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(Redirected from Load shed)
A room during load shedding at night in West Bengal, India.

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.

Rolling blackouts are a measure of demand response if the demand for electricity exceeds the power supply capability of the network. Rolling blackouts may be localised to a specific part of the electricity network, or they may be more widespread and affect entire countries and continents. Rolling blackouts generally result from two causes: insufficient generation capacity or inadequate transmission infrastructure to deliver power to where it is needed.

Rolling blackouts are also used as a response strategy to cope with reduced output beyond reserve capacity from power stations taken offline unexpectedly.

In developing countries

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Rolling blackouts are a common or even a normal daily event in many developing countries,[1] where electricity generation capacity is underfunded or infrastructure is poorly managed. In well managed under-capacity systems blackouts are planned and schedules are published in advance to allow people to work around them. In poorly managed systems they happen without warning, typically whenever the transmission frequency falls below the 'safe' limit.

These have wide-ranging impacts, and can effect the expectations of communities. For example, in Ghana dumsor describes the widespread expectations for intermittent unexpected power outages due to rolling blackouts.

Iran

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In 2021 Iran regularly conducted large blackouts nationwide.[2]

In July 2024, the government started 4 hour per day blackouts affecting homes and industries despite 40 degrees Celsius heat waves, and the severity of power shortages exceeded worst case scenario predictions.[3][4][5]

In 2024 November 10th government began reimplementing blackouts nationally.[6]

Philippines

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Remote areas or off-grid areas are the most vulnerable to power supply issues.[7] Areas placed with under yellow and red alerts are subject to rolling blackouts.[8][9]

South Africa

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Since 2007, South Africa has experienced multiple periods of rolling blackouts which are locally referred to as load shedding by the state-owned energy company Eskom. This was initially caused by the country's demand for electricity outstripping supply, and as time progressed, later exacerbated by ageing power infrastructure, poor maintenance, and the slow completion of new power stations. It was recently revealed by Eskom's former spokesperson Sikhonathi Mantshantsh, that widespread tender corruption and the sabotage of power infrastructure by employees[10][11] is one of the primary reasons for continuing load shedding. This has caused severe damage to the South African economy and has played a large part in limiting the country's economic growth.

Ukraine

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Power generators in Dnipro during the blackouts, 2024

In late 1990s in Ukraine there were frequent daily scheduled electricity blackouts throughout the country's power system due to miners' strikes, the destruction of the coal industry in 1991–1996, the hidden privatization of energy companies and barters in the energy industry, which included even nuclear power.[12]

During 2022 invasion of Ukraine, Russia conducted multiple attacks on energy infrastructure of Ukraine.[13][14][15][16] On October 23 rolling blackouts were introduced in Kyiv and its oblast.[17][18] Rolling blackouts were introduced in all Ukrainian regions on 25 October 2022.[19]

In 2024 Ukraine again faces an unprecedented energy crisis due to Russia's destruction of energy infrastructure, re-introducing rolling blackouts. Approximately 70% of the country's thermal generation amount was either damaged or under occupation by May 2024.[20]

Egypt

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In summer 2023, with the unprecedented heatwave that hit the country, the Egyptian government announced it will start a scheduled blackout across all major cities for 1 hour every day until the heat wave ended. However the blackouts remained well into the winter and were increased to 2 hours a day. In summer 2024, the temperatures rose even higher and the schedule changed to 3 hours every day with reports of unplanned cuts in Alexandria, Cairo and other cities where some places faced over 6 hours without electricity for 3 consecutive days.[21]

In developed countries

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Rolling blackouts in developed countries sometimes occur due to economic forces at the expense of system reliability,[22][23] or during natural disasters such as heat waves.[24]

Japan

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After the 2011 Tōhoku earthquake and tsunami, Tokyo Electric Power Company implemented rolling blackouts. Its service area were divided to five blocks and blackouts were implemented from 6:20 to 22:00. The schedule from 15 to 18 March 2011 was as follows:[25][26]

Time 15 March 16 March 17 March 18 March
6:20–10:00 Block 3 Block 4 Block 5 Block 1
9:20–13:00 Block 4 Block 5 Block 1 Block 2
12:20–16:00 Block 5 Block 1 Block 2 Block 3
15:20–19:00 Block 1 Block 2 Block 3 Block 4
18:20–22:00 Block 2 Block 3 Block 4 Block 5

USA

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In California rolling blackouts during 2000–01 California energy crisis occurred in June 2000, January, March and May 2001,[27] and August 2020.[28][29] The 2021 Texas power crisis involved rolling blackouts caused by the February 13–17, 2021 North American winter storm and lack of winterization.[30] The Late December 2022 North American winter storm resulted in rolling blackouts in parts of the eastern US.[31][32][33]

Other

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Effects

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Intermittent access to electricity causes major economic problems for businesses, which incur costs in the form of lost resources, reduced patronage, or curtailed production if electrical equipment—for example refrigeration, lighting, or machinery—abruptly stops working.[34] Businesses in areas that are subject to regular blackouts may invest in backup power generation to avoid these costs, but power backup is itself a cost because generators must be purchased and maintained and fuel must be regularly replenished.

Scheduling

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When blackouts are scheduled in advance, they are easier to work around.[35]

The speed at which blackouts roll may be adjusted so that no blackout lasts longer than a certain limit. For instance, in Italy, the PESSE (Piano di Emergenza per la Sicurezza del Sistema Electrico, Emergency plan for national grid safety) does not permit a controlled blackout longer than 90 minutes. In Canada, blackouts have been rolled so that no area had to spend more than one hour without power.[36][37]

Causes

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In some countries, generating capacity is chronically below demand.[38][39][40][35] Assorted factors may prevent adequate investment in generation.[41] Alternately, generating capacity may temporarily decrease below demand due to power station outages[42] or loss of renewable capacity due to the wind dropping[37] or the sun shining less.[43] Natural disasters can also abruptly reduce supply by damaging power plants.[41] A lack of fuel makes some types of power plant useless.[44] Industrial accidents and poor maintenance can also take generation capacity offline.[45][46] Conflict can disrupt fuel supply,[47] as well as damage or destroy generating and delivery infrastructure.[48][19]

In electricity grids where power generators are paid a flexible market rate, power suppliers sometimes deliberately keep the generating capacity too low, or fake accidents that take capacity offline, to jack up prices.[49][37]

Demand spikes can also cause blackouts. Unusually hot[35][50] or cold weather[51][52][53][36] can cause demand spikes. Independent system operators may introduce rolling blackouts in anticipation of demand spikes, based on often arbitrary minimum thresholds of electricity reserves.[29]

In the case of South Africa, failing and aged infrastructure, lack of maintenance and alleged corruption in the country's African National Congress-led government in the running of their primary electricity provider, Eskom, is the direct cause of rolling blackouts.[citation needed]

References

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  2. ^ Berger, Miriam (16 January 2021). "Massive blackouts have hit Iran. The government is blaming bitcoin mining". The Washington Post.
  3. ^ "قطع بی‌سابقه برق در خیابان میرزای شیرازی/ مسئولان پاسخ روشن نمی‌دهند - خبرآنلاین".
  4. ^ "نماینده مجلس : کمبود برق به جایی رسیده در دمای بالای ۴۵ درجه ، برق خانگی را قطع می‌کنند".
  5. ^ "توانیر: مصرف برق از بدبینانه‌ترین سناریوی پیش‌بینی شده هم عبور کرد".
  6. ^ "شرکت توانیر از قطع برق و آغاز خاموشی‌های زمان‌بندی‌شده خبر داد".
  7. ^ Galvez, Daphne (31 January 2023). "Rotational brownouts to hit 1.3 million houses in 2023 — DOE". Philippine Daily Inquirer. Retrieved 19 June 2024.
  8. ^ "'Red Alert Strikes Back' Luzon grid may endure rotational brownouts". Manila Bulletin. Retrieved 19 June 2024.
  9. ^ Mercurio, Richmond (23 January 2023). "Concerns raised over looming energy crisis". The Philippine Star. Retrieved 19 June 2024.
  10. ^ Koko, Khaya (17 January 2023). "'You are sabotaging us ahead of 2024 elections,' ANC tells Eskom". The Mail & Guardian.
  11. ^ Jacobs, Shaun (12 June 2023). "Eskom sabotage of 'catastrophic proportions'". Daily Investor.
  12. ^ "Хроніки енергоолігархії: 20 років залежності - Главком". web.archive.org. 28 January 2021. Retrieved 20 November 2024.
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  21. ^ Nader, Jacob Wirtschafter and Mina (1 July 2024). "Blackouts and Extreme Heat Plague Egypt as Government Extends Rolling Electricity Cuts". The Media Line. Retrieved 20 November 2024.
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  23. ^ "The California Crisis". Frontline.
  24. ^ Harvy, Ben; Shepherd, Tory (8 February 2017). "Rolling Blackouts Ordered as Adelaide Swelters in Heatwave". news.com.au.
  25. ^ "Implementation Plan of Rolling Blackout on and After Tue, March 15, 2011" (Press release). Tokyo Electric Power Company. 14 March 2011.
  26. ^ "Shūkan Keikaku Teishi Imēji" 週間計画停止イメージ [Weekly Planned Outage Image] (PDF) (in Japanese). Tokyo Electric Power Company.
  27. ^ Brown, Marilyn A. (2004). "Obstacles to Energy Efficiency". Encyclopedia of Energy. Elsevier Inc. pp. 465–475. doi:10.1016/B0-12-176480-X/00172-8. ISBN 9780121764807. Retrieved 14 June 2022.
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  29. ^ a b Penn, Ivan (16 August 2020). "Rolling Blackouts in California Have Power Experts Stumped". The New York Times. Retrieved 29 May 2024.
  30. ^ Walsh, Dominic Anthony (16 February 2021). "What's Happening in Texas With the State's Power Grid". NPR.
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  33. ^ "Thousands of Middle Tennesseans impacted by power outages during dangerous cold". News Channel 5 Nashville (WTVF). 23 December 2022. Retrieved 23 December 2022.
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  35. ^ a b c "Unscheduled loadshedding irks people in Punjab". The Nation. 2 October 2011.
  36. ^ a b "Newfoundland outages worsen amid sudden 'generation problems'". 5 January 2014.
  37. ^ a b c Gerein, Keith (9 July 2012). "Rolling electricity blackouts strike Edmonton and across the province". The Vancouver Sun. Archived from the original on 18 July 2012.
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  39. ^ Range, Jackie (28 October 2008). "India Faulted for Failure to Improve Power Supply". The Wall Street Journal.
  40. ^ "India offers Pakistan electricity to curb load-shedding". The Express Tribune. 20 April 2011.
  41. ^ a b "Mail and Guardian – Govt chose guns over power stations". Mg.co.za.
  42. ^ "ERCOT may initiate more blackouts Wednesday night, Thursday morning". The Dallas Morning News. 2 February 2011. Archived from the original on 10 May 2011. Retrieved 2 February 2011.
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  44. ^ "Tripped coal stations add to load shedding burden". Business day live. 5 December 2014. Retrieved 6 December 2014.
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  47. ^ Ukraine turns off reactor at its most powerful nuclear plant after 'accident', The Independent (28 December 2014)
    Ukraine Briefly Cuts Power to Crimea Amid Feud With Russia Over NATO, New York Times (DEC. 24, 2014)
    Coal import to help avoid rolling blackouts in Ukraine — energy minister, ITAR-TASS (December 31, 2014)
    Rolling blackouts in Ukraine after nuclear plant accident
    Mashable (Dec 03, 2014)
    Ukraine to Import Coal From ‘Far Away’ as War Curtails Mines, Bloomberg News (Dec 31, 2014)
  48. ^ "Ukraine war: Kyiv set for longer power cuts after air strikes". BBC News. 29 October 2022. Retrieved 11 November 2022.
  49. ^ Lauren Johnston (2 June 2004). "Enron tapes anger lawmakers". CBS Evening News.
  50. ^ "SA heatwave forces blackouts to cope with electricity demand, angering Government". ABC News. 9 February 2017.
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  52. ^ Situation Report No. 4 – Tajikistan – Cold Wave/Compound crisis (25 February 2008) Archived 21 May 2011 at the Wayback Machine United Nations Office for the Coordination of Humanitarian Affairs
  53. ^ Heinz, Frank (2 February 2011). "Outages Suspended, But Conservation Critical". NBC 5 Dallas-Fort Worth.