When the Bough Breaks

Digital Object Identifier 10.1109/MPE.2014.2331899 Date of publication: 18 August 2014

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managing the aftermath of severe impacts on electrical power system grids due to extreme weather events resulting from climate change are all receiving growing attention. recent severe events in north america and across the globe have stressed the ability of electrical utilities to maintain the continuity and reliability of supply, with many custom-ers experiencing extended power outages. hurricane sandy, recent severe winter snow and ice storms in the northeastern United states and eastern canada, supercyclone Phailin in india, and typhoon hai-yan in the Philippines are prime examples. this article is sponsored by members of the climate change technology subcommittee of

When

the Bough

Breaks

Managing Extreme Weather

Events Affecting Electrical

Power Grids

By Nicholas Abi-Samra,

James McConnach,

Subrata Mukhopadhyay,

and Bartosz Wojszczyk

the ieee Power & energy society energy development and Power generation committee, whose chair is tom Baumann.

Major North American Events: Impacts,

Aftermath, and Lessons Learned

Superstorm Sandy, October 2012

superstorm sandy made landfall in the continental United states on the evening of 29 october 2012, at which time it was officially classified as a posttropical cyclone. By the end, sandy’s multiple weather systems had affected 24 states in the most densely populated region of the country, from florida to Maine and reaching as far west as Michigan and wisconsin. the estimated damage from sandy in the United states was put at Us$65 billion.

due to sandy, entire neighborhoods in coastal areas were severely damaged, ground transportation was disrupted for days, and a quarter of the cellphone sites in ten states went down. sandy’s wrath hit the electricity grid hard: more than 8.5 million households and businesses experienced power out-ages, which in some cases lasted for weeks. wastewater treat-ment plants lost power, sending billions of gallons of raw and partially treated sewage into the region’s waterways. in new York city, the east river overflowed its banks, flooding large sections of Lower Manhattan. Battery Park had a water surge of 13.88 ft. sandy’s storm surge sent water sloshing into many underground substations in new York city, leading to wide-spread outages. for the grid, flooding is considered the worst of extreme weather events because of the long-term damage that floodwater can do to power substations and underground electrical systems. restoring a flooded substation takes much longer than restoring a downed power line that’s been dam-aged by ice or wind because you have to deal with the large amounts of water, rust, and mud left trapped in the structure.

sandy made it painfully clear how fragile the aging U.s. power system infrastructure is. it also highlighted the fact that hardening the grid to withstand all extreme weather is impos-sible and unaffordable. sandy reinforced the notion that what is needed is a holistic approach based on grid resiliency. resil-iency measures aren’t intended to prevent damage from extreme weather; rather, they minimize the impact of the resulting dam-age by enabling electric facilities to continue operating and restore service quickly when outages occur. such an approach would include traditional tactics, such as upgrading power poles and trimming trees near power lines. But it also encompasses newer approaches that let operators quickly reconfigure the system when portions of the grid go down, such as the use of

microgrids and energy storage. implicit in such plans is the need to ensure uninterrupted power to critical sites such as oil and gas refineries, water-treatment plants, and telecommunication net-works, as well as gasoline stations, hospitals, and pharmacies. some of the U.s’s leaders seem receptive to such approaches.

The 2013 North American Ice Storm

this was a severe ice storm that struck the central and east-ern portions of canada and the northeasteast-ern United states from 20 to 23 december 2013. one of the hardest-hit areas was southern and eastern ontario, including the city of toronto. this ice storm marked the most severe storm of its kind in ontario since the 1998 ice storm that affected east-ern ontario and southeast-ern Quebec.

Preparations

in toronto, utility workers prepared for possible downed power lines and officials warned residents to expect power outages.

Impacts

hydro one, which serves mostly rural areas of ontario, reported more than 130,000 power outages at the height of the storm. thousands of customers remained without power well after christmas day. toronto, canada’s largest city, was among the areas hardest hit by the ice storm. the first wave of freezing rain began on 20 december; it coated the city in a significant but manageable amount of ice. the second and more power-ful wave of rain struck the city in early morning hours of 22 december. Utility poles and tree branches collapsed under the enormous weight of the thick ice accumulation. at the height of the storm, more than 300,000 toronto hydro customers were without power or heat. the city of toronto simultaneously opened and operated 13 community reception centers and 13 police facility community warming centers, providing tempo-rary sleeping accommodations, food, water, hygiene kits, and other resources. the warming centers were open around the clock, offering those who lost their power a warm place to sleep and eat until their power was restored. By christmas eve, four days after the storm, there were still 69,800 customers without power across the city. approximately 1,000 people spent christ-mas eve in the warming centers. on 29 december 2013, one week after the storm, hydro one diverted its crews to assist toronto hydro with restoration efforts to the more than 6,000 people that still remained without power in the city. in addi-tion to hydro one, crews were called in from ottawa, windsor, Michigan, and as far away as Manitoba to help restore power to the city by 1 January. west of toronto, crews were called in

The importance of improved forecasting,

emergency preparedness strategies, and grid safety positioning

strategies should be recognized.

from essex, goderich, guelph, haldimand, niagara, oakville, st. thomas, and tilsonburg.

Aftermath

following the ice storm, thousands of tree branches littered the streets and sidewalks of toronto. in some case, roads had to be closed because of the large tree limbs blocking the streets. further snow accumulations a few days after the storm resulted in more downed branches and power lines. the city announced that debris-clearing operations would begin on 3 January 2014. the operation took more than two months to fully complete. By the end of the cleanup, a signifi-cant percentage of the city’s tree coverage was lost. toronto hydro reported that an estimated c$12.9 million was spent on the ice storm. that includes around c$1 million in lost revenue, c$10 million on labor, and another c$2 million for materials such as conductors.

Lessons Learned

the lessons learned from these events include the following:

✔ there is a need for greater understanding and awareness on the part of all interested parties, including custom-ers, of the modern-day critical dependence of densely populated areas on key infrastructure services such as electricity, gas, water, transit, and communications and of the interdependence of these services.

✔ the importance of adequate staffing, skills, and coop-eration of utility employees—not just those from the affected area but also those from neighboring areas and nearby utilities—became clear.

✔ there is a need for coordinated mobilization of emer-gency resources, including both paid staff and volun-teers, to provide assistance to those most in need, e.g., the aged and infirm.

✔ frequent and accurate communications to the public regarding impacts and restoration progress are crucial. customers like to know the severity, timing, and dura-tion of impacts and when they can expect to have power restored. reliable ongoing communication with utility restoration crews is also essential for monitoring progress.

28 N 26 N 24 N 22 N 20 N 18 N 16 N 14 N 12 N 10 N 8 N 80 E 82 E 84 E 86 E 88 E Longitude Latitude 90 E 92 E 94 E 96 E 98 E Past Track _{Forecast Track}

TS Cat 1

TD TS Cat 1 Cat 2 Cat 3 Cat 4 Cat 5 Prior Wind-Affected Areas

figure 1. The track of Supercyclone Phailin.

Before, during, and after the cyclone,

rich experience was gained about dealing with

such calamities.

✔ there is a need for intensive debriefing sessions to iden-tify lessons learned, ideas and opportunities to improve emergency preparedness, communications, and restora-tion activities so as to provide greater resiliency to the next extreme event.

Other Extreme Events

Moore (Oklahoma) Tornado, 20 May 2013

the oklahoma department of emergency Management reported 24 deaths and 377 injuries as a result of this tornado, with an estimated 1,150 homes destroyed and Us$2 billion in damages. entire subdivisions were obliterated, including util-ity infrastructure, and houses were flattened in a large swath of the city. Most of a neighborhood just west of the Moore Medical center was destroyed. witnesses said the tornado more closely resembled “a giant black wall of destruction” than a typical twister.

Alberta (Canada) Flooding, June 2013

government officials called these floods the worst in alberta’s history. four people were confirmed dead as a direct result of the flooding, and more than 100,000 people were displaced throughout the region. total damage to infrastructure, homes, and businesses was estimated to exceed c$5 billion, and in terms of insurable damages, it was the costliest disaster in canadian history, at c$1.7 billion.

International Events: Impacts,

Aftermath, and Lessons Learned

Supercyclone Phailin, India, 12 and 13 October 2013

on 12 and 13 october 2013 the devastating supercy-clone Phailin, named on 9 october 2013 by the indian

Meteorological department (iMd) of the government of india, struck the east coast of peninsular india—mainly the state of odisha and then to some extent andhra Pradesh, on the western shore of the Bay of Bengal. the storm’s track over time is shown in figure 1.

Preparations

due to progress in various technologies in areas such as weather forecasting, communication, and other information support systems, it was possible to a large extent to predict the level of disturbance due to Phailin ahead of time. accord-ingly, preventive measures were able to reduce the impact as a whole on power system operation, from generation to uti-lization of electricity through transmission and distribution.

Impacts

in this case, although the severity of Phailin on the saffir-simp-son hurricane scale (sshs) rose as high as 5, the loss of life and property was much less over a wide area than that due to a similar earlier event, the odisha supercyclone of 29 october 1999. with online data about the status of traditional equipment monitored and transmitted to control centers at various levels, good overall observation of the grid was possible. in addition, due to large-scale deployment of phasor measurement units, it was possible this time to make use of accurate and quick wide-area monitoring as realized using the concept of the smart grid.

Lessons Learned

Before, during, and after the cyclone, rich experience was gained about dealing with such calamities. the value of a strategic plan that anticipated potential events, of taking cor-rect and rapid decisive actions in the wake of the disturbance, and of arranging for early restorative action so as to minimize the disruption of electric supply became evident. this was achieved through:

✔ shutdown and/or backing down of critical generating units and transmission lines

✔ maintenance of communication links

✔ deployment of an emergency restoration system and additional equipment as an alternative means of transmission

✔ utilization of large-scale portable diesel generating sets for decentralized generation

✔ engaging emergency response teams from power utili-ties at all critical substations and control centers ✔ curtailment of market trades during extreme

contin-gencies, with system operation as the highest priority. Monday Sunday Saturday Philippines Vietnam Friday (8 November 2013)

figure 2. The track of Supertyphoon Yolanda.

This was a severe ice storm that struck the central

and eastern portions of Canada and the northeastern United States

from 20 to 23 December 2013.

Supertyphoon Yolanda (International Name: Haiyan), Philippines, November 2013

the Philippines is an archipelago situated in the Pacific’s ring of fire with more than 7,000 islands and 36,000 km of coastline. the Philippines is highly vulnerable to the impacts of natural disasters, including the global phenomenon of climate change. Based on the 2012 World Risk Report pub-lished by the United nations University institute of environ-ment and human security (UnUehs), the Philippines is the country with the third-highest disaster risk worldwide, with a risk index of 27.98% of its population.

Impacts

in november 2013, the Philippines was hit by supertyphoon Yolanda (international name: haiyan), the most powerful typhoon of the year and the fourth-strongest storm ever recorded in the world, with sustained winds of 315 mi/h and gusts up to 380 mi/h. disturbing mostly the Visayas region (see figure 2), Yolanda left the country with massive destruction of infrastructure and agri-culture that affected about 16 million filipinos (about 17% of the population). the estimated total cost of damages was at the level of 36.7 billion pesos (about Us$0.9 billion), with an estimated 0.5% gross domestic product (gdP) impact at the country level.

Yolanda interrupted major food, water, telecommunica-tions, and electric power supply services. the national grid corporation of the Philippines (ngcP) announced that more than 2,000 major distribution and transmission facilities were damaged, with many locations sustaining 100% infrastructure destruction. it took approximately two months to complete repair and restoration activities for the major (bulk) electric infrastructure; many remote locations are still without a sus-tainable power supply, however.

Lessons Learned

as a result of supertyphoon Yolanda, MeraLco (the larg-est distribution electric utility in the Philippines) and other energy stakeholders initiated a discussion about a poten-tial country-level strategy to include hardening across the entire grid (new design and construction standards), smart grid technology deployment in the context of an integrated approach to operational and information technology across all voltage levels, a “last mile” telecommunication platform, advanced network automation, and microgrid solutions.

Conclusions and Recommendations

✔ the importance of improved forecasting, emergency preparedness strategies, and grid safety positioning strategies should be recognized.

✔ the development of microgrids to prevent total system collapse and faster recovery of the grid is important. ✔ the widespread use of cellphone communications to

aid in collecting data and obtaining status reports on the numbers and timing of outages and restorations is recommended.

✔ further technology innovations for grid hardening and resiliency are required.

✔ high-priority r&d needs for very large-scale events must be identified and pursued.

For Further Reading

n. c. abi-samra. (2013. nov.). one year later: superstorm sandy underscores need for a resilient grid. IEEE Spectrum, [online]. available: http://spectrum.ieee.org/energy/the- smarter-grid/one-year-later-superstorm-sandy-underscores-need-for-a-resilient-grid

december 2013 north american ice storm. [online]. available: en.wikipedia.org/wiki/december_2013_north_ american_ice_storm

cyclone Phailin: Meteorogical history. [online]. available: http://en.wikipedia.org/wiki/cyclone_Phailin#Meteorological_ history

Acknowledgments

this article was written by the climate change technology subcommittee of the ieee Power & energy society energy development and Power generation committee, with the key contributors being nicholas abi-samra, James Mcconnach, subrata Mukhopadhyay, and Bartosz wojszczyk.

Biographies

Nicholas Abi-Samra is with dnV gL, san diego, cali-fornia.

James McConnach recently retired from castle hill engineering services, Montreal, canada.

Subrata Mukhopadhyay is with gtB institute of tech-nology, new delhi, india.

Bartosz Wojszczyk is with Manila electric company, Manila, the Philippines.

p&e

The Philippines is highly vulnerable to the impacts

of natural disasters, including the global phenomenon

of climate change.