SEPTEMBER 23-24, 2022 S TORM OUTAG E ANALYSIS REPORT 0 METHODOLOGY • The report assigns the temperature and wind data based on the highest observed speeds that occurred during the event. • Full accounting of hourly weather data is provided as an appendix for the eight representative stations used. • The map in the provincial highlights slide is divided into NS Power operational depot boundaries. • Provincial highlights in slides 6-8 illustrate outages with the largest CHI impact and overall customer impact. These are intended to give an indication of the overall event impacts and restoration process. • “Unique Customer Impacts” refers to the total number of unique customers who experienced an outage during the event. A customer who experienced a power outage twice during an event counts as a single unique customer in this tally. “Total Customer Impacts” refers to the total number of customers impacted during an event. A customer who experienced a power outage twice during an event is counted twice in this tally. • Following the direction of NS Power’s weather consultant, the data needed for this report to present a useful analysis typically requires an examination of eight representative stations. This provides a view of the magnitude, as well as the timing of the strong winds during an impactful storm event. Since this analysis also involves forecast verification, the same list of trusted, high-quality stations is used to ensure results are aligned and benchmarked with the proper historical context. This is also a practical meteorological rationale to focus on the impact and magnitude of an overall event as opposed to the wind speed and gusts at specific sites. Wind speeds and gusts vary significantly due to local effects and conditions such as, but not limited to, shelter from trees, exposed hilltop, sheltered valleys, or coastal wind effects (i.e. stations located on coastline observe winds that do not extend inland). This site-specific information is useful when determining potential local wind enhancements and how to mitigate; however, it historically has limited added value in the province-wide analysis undertaken by NS Power to date. 1 SECTION 1: WEATHER EVENT SUMMARY • Hurricane Fiona brought an extended period of extreme winds and heavy rain to Nova Scotia on Sept 23 and 24, 2022. • The historic storm caused significant and widespread damage to NSPI’s transmission and distribution system and at the height of the storm approximately 405,000 customers (across the province) lost power. • At landfall, Fiona retained significant strength and was equivalent to a Category 2 hurricane. • A very large wind field of 100+ km/h gusts extended more than 220 km to the west of the storm center. • The central pressure of 931 hPa reported during landfall was the lowest pressure reported for any storm in Canadian history. • Wind gusts above 100 km/h persisted for 4 hours in Metro, 8 hours in Cape Breton East and up to 13 hours in the Northeast. • Areas along both the Atlantic Coast and Northumberland Strait experienced extreme prolonged winds resulting in unprecedented damage to poles and wire. Uprooted trees from outside cleared rights of way tore down power lines. 2 • Fiona impacted an area almost double in size to that of Dorian in 2019. This resulted in extraordinary damage to trees and electrical equipment in impacted areas throughout the province. It is the 10th costliest extreme natural disaster to occur in Canada and among the most intense and damaging storms in Canadian history. • Significant coordination and partnership occurred throughout restoration with the Provincial Emergency Management Office (EMO), Department of Natural Resources and Renewables and the Canadian Armed Forces. Satellite Emergency Operation Centres were set up in Truro and Sydney and additional large-scale staging areas for crews were established at the Pictou Wellness Centre and the Mayflower Mall. • Large trees from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. In some cases, tree diameters exceeded 3-4 feet and required heavy equipment, cranes and hours of work to be removed. Cases of up rooted tree diameter exceeding 5ft were recorded. • NS Power invests $20 - 25 million on average each year in tree trimming and clearing rights of way of trees, totaling approx. $100M over the last five years. SECTION 2: WIND OBSERVATIONS 3 Region Forecast (24Hr Prior) Actuals Precipitation Wind Gust (km/h) Weather Station Temp (°C) Weather Observation Sustained Wind (km/h) Max Wind Gust (km/h)* Wind Direction (Degrees) Annapolis Valley (V) Rain 90 Greenwood 9 Rain 69 91 280 South Shore (SS) Rain 90 Yarmouth 10 Rain 50 81 330 Northern Nova Scotia (N) Rain 130 Nappan/ Debert 10 Rain 67 91 340 Northeast (NE) Rain 140 Caribou Pt. 13 Rain 102 133 360 Metro (M) Rain 125 Halifax Airport 10 Rain 76 111 340 Eastern Shore (ES) Rain 140 Beaver Is. 12 Rain 126 150 360 CB West (CBW) Rain 130 Grand Étang 15 Rain 91 139 90 CB East (CBE) Rain 140 Sydney 12 Rain 96 141 150 High winds impact trees, causing them to fall onto power lines, and can also damage equipment. *Gust values are taken from the representative Environment Canada stations in each of the eight weather regions. Their recorded results are sampled once per hour and may not reflect the highest actual gust throughout the entire hour. The location of some stations may also not capture locally higher gusts along coasts or other exposed areas. Certain additional stations in these regions reported even higher gusts than noted above, such as Arisaig recording a gust of 179km/h. SECTION 3: OUTAGE SUMMARY Metric Result Unique Customers Impacted 424,486 Customer Interruptions 752,391 Total Customer Hours 30,744,918 Event Start Time 23/09/2022 20:48 Event End Time* 08/10/2022 19:00 Main Regions Impacted Metro, NE, N, ES, CB Outage Restoration Profile: *Event End Time is noted as the beginning time of the final outage attributable to the storm event. Combined with the start time, these two times provide the bounds of the outage events included in storm analysis. As shown in the graph above, restoration of customers continues beyond event end time. Restoration began once winds fell below safe levels at 12:00 PM 24/09/2022 and continued throughout the event until the last customer was restored at 16:46 on 10/10/2022. Outages due to wind gusts and damaged trees and equipment continued to occur for days after the storm. 95% of impacted customers were restored by the afternoon of Oct 3rd. CB West CB East Metro Northern NorthEast Eastern Shore SouthShore Valley SECTION 4: PROVINCIAL IMPACT SUMMARY 5 This map presents a geospatial view of the overall impact to the province by customer hours of impact (CHI). This map is a symbolized view of impacted areas by 8 geographical zones. Nova Scotia experienced the most severe hurricane force wind weather event on record across the province on Sep 23 and 24, 2022. Fiona made landfall equivalent to a Category 2 hurricane with peak gusts over 150 km/h, destroying power lines and uprooting trees. Northeast NS experienced 13 consecutive hours with gusts over 100 km/h. Over 1,500 field resources were mobilized to restore power in affected areas, including the largest pre-storm staging in NS Power history. Significant coordination with municipal, provincial, and federal counterparts through the provincial Emergency Management Office (EMO), Department of Natural Resources and Renewables and the Canadian Armed Forces. Satellite EOCs were setup in Truro and Sydney and additional large-scale staging areas for crews were established at the Pictou Wellness Centre and the Mayflower Mall. Legend (CHI) Red >50,000 Orange >25,000 Yellow >10,000 Green <10,000 *Customers Impacted (CI) reflects total not unique impacted Zone Customer Interruptions (CI)* Unique Customers Impacted Customer Hours of Interruptions (CHI) Valley 57,806 38,587 665,634 South Shore 59,459 28,400 635,356 Northern 41,974 22,154 2,391,604 Northeast 127,683 64,177 9,035,083 Metro 331,481 196,862 9,027,322 Eastern Shore 7,311 5,772 599,697 CB West 4,273 4,165 78,834 CB East 122,404 64,369 8,311,389 Total 752,391 424,486 30,744,918 Customers Restored within x hours of Restoration Onset* *This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of storm restoration, rather than the start of their individual outage. ** 99.89% of customers were restored prior to the end of the storm period. Average restoration time for the storm was just over 100hrs. Provincial % Within 6 Hrs 16.90% Within 12 Hrs 25.51% Within 24 Hrs 34.83% Within 48 Hrs 51.85% During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. SECTION 4: PROVINCIAL HIGHLIGHTS 6 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust* (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Valley 9/23/2022 23:31 Greenwood 10 43 61** 330 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the recloser. 1070 40.86 South Shore 9/24/2022 00:36 Yarmouth 10 48 70** 340 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the recloser. 1528 34.27 Northern 9/23/2022 23:27 Nappan/ Debert 10 46 61*** 360 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the recloser. 2457 76.81 Northeast 9/23/2022 22:52 Caribou Pt. 12 61 82 10 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the protective device. 1606 138.17 Metro 9/23/2022 23:52 Halifax Airport 10 48 80 350 Tree Contacts Falling Trees High winds caused trees to damage conductor and tear down poles, opening the recloser. 2091 107.16 Eastern Shore 9/24/2022 00:16 Beaver Island 12 126 150 360 Tree Contacts Falling Trees Extreme winds and gusts caused trees to land on primary lines, opening the recloser. 543 206.87 CB West 9/24/2022 01:11 Grand Étang 15 65 87 10 Tree Contacts Falling Trees High winds caused trees to damage conductor and tear down poles, opening the recloser. 904 46.23 CB East 9/24/2022 02:22 Sydney Airport 18 72 122 110 Adverse Weather Wind High winds and gusts caused extensive damage to all feeders from 11S substation, ultimately opening the substation recloser. 5565 225.07 *Wind gusts shown are those at or preceding the event. Higher gusts occurring after the event onset would impact crew’s ability to restore. High winds brought trees and lines into contact or damaged equipment. Large trees, often from outside cleared rights of way, were uprooted or snapped, tearing down power line infrastructure. NS Power invests $20 –25 million on average each year in tree trimming and clearing rights-of-way of trees and vegetation. ***Gusts for the Northern region are recorded at a representative station significantly inland from the Northumberland Strait and farther West than the areas of greatest damage. Based on other observations in the general area (stations at Caribou Pt., Charlottetown, and Moncton all recorded gusts above 100 km/h) coastal areas of the region were likely subject to higher gusts than the representative station indicates. In addition, recorded results are sampled once per hour and may not reflect the highest actual gust throughout the entire hour. **The highest gusts and damage in these zones occurred in the eastern end of the regions closer to Metro. The two representative stations (especially Yarmouth) are located farther west in the regions and may not have observed the highest gusts experienced. SECTION 4: PROVINCIAL HIGHLIGHTS – TOP 5 EVENTS BY CUSTOMERS IMPACTED 7 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Metro 9/24/2022 04:29 Halifax Airport 10 80 111 310 Adverse Weather Wind High winds and extreme gusts caused a tree to land on the primary line, opening the recloser. 5298 16.74 Metro 9/29/2022 14:23 Halifax Airport 18 6 111 330 Adverse Weather Wind Emergency repairs to a damaged cutout due to extreme winds and gusts in days preceding. 4556 0.25 Metro 9/23/2022 23:58 Halifax Airport 10 48 80 350 Adverse Weather Wind High winds caused trees to land on the primary lines, opening the recloser. 4232 27.18 Metro 9/25/2022 03:24 Halifax Airport 10 30 111 250 Adverse Weather Wind High winds and extreme gusts caused trees to land on the primary lines, opening the recloser. 4231 2.18 Metro 9/24/2022 04:24 Halifax Airport 10 80 111 310 Adverse Weather Wind High winds and extreme gusts caused trees to land on the primary lines, opening the recloser. 4157 13.48 Large trees, often from outside cleared rights of way, were uprooted or snapped, tearing down power line infrastructure. NS Power invests $20 -25 million on average each year in tree trimming and clearing rights of way of trees. SECTION 4: PROVINCIAL HIGHLIGHTS – TOP 5 EVENTS BY DURATION 8 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction Cause Sub-Cause Description Customers Impacted Duration (Hours) Northeast 9/24/2022 00:40 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to land on the line, bringing down the customer'sline between poles and to the house. 1 397.35 Northeast 9/24/2022 00:09 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to land on the line, bringing down the customer'sline to the house. 3 396.36 Northeast 9/24/2022 00:09 Caribou Pt. 13 69 89 360 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, bringing down the customer's line to the house. 1 395.82 Northeast 9/24/2022 00:09 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to damage conductor and tear down poles, bringing down the customer's line to the house. 4 395.58 Northeast 9/24/2022 00:27 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to land on the line, opening the transformer fuse. 1 395.31 During the initial restoration phase of Hurricane Fiona, NS Power’s restoration hierarchy was implemented to prioritize critical infrastructure as established by the provincial EMO. This approach ensured that critical infrastructure such as water pumping and sewer stations, fuel stations, and critical emergency services were prioritized for restoration, but did contribute to a slower pace of overall customer restoration during the early stages of the event. Following EMO priorities, crews were focused on outage events impacting larger customer counts and then continued into smaller outage events. SECTION 4: ZONE SUMMARY IMPACT SUMMARY – VALLEY 9 The Valley region experienced winds near forecast and exceeded warning levels during the event. Peak gusts recorded at Greenwood were 91km/h. High winds contributed to tree contacts, particularly in the Eastern Valley. Outage Summary: Customers Impacted: 57,806 Customer hours of interruption: 665,634 Full Restoration*: 356.6 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of the restoration, rather than the start of their individual outage. Average restoration time for this region was 33.21 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start Valley % Within 6 Hrs 60.66% Within 12 Hrs 70.01% Within 24 Hrs 76.50% Within 48 Hrs 89.97% 100% Adverse Weather Cause of Outage (CHI) Wind 27% 73% Cause of Outages (CHI) Tree Contacts Adverse Weather 1 0 SECTION 4: ZONE IMPACT SUMMARY – VALLEY TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Valley 9/24/2022 16:37 Greenwood 13 37 91 280 Tree Contacts Falling Trees High winds caused trees to make contact with the line, breaking the service pole to the customer’s property. 1 186.75 Valley 9/25/2022 07:51 Greenwood 9 13 91 240 Tree Contacts Falling Trees High winds caused trees to make contact with the line, breaking two poles. 1 177.48 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Valley 9/24/2022 16:34 Greenwood 13 37 91 280 Tree Contacts Falling Trees High winds caused trees to make contact with the primary line, opening the recloser. 3165 0.33 Valley 9/24/2022 08:46 Greenwood 9 44 76 290 Adverse Weather Wind High winds caused a poleto break. 2071 18.08 Duration Customer Impact Large trees, often from outside cleared rights of way, were uprooted or snapped, tearing down power line infrastructure. NS Power invests $20 - 25 million on average each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE SUMMARY IMPACT SUMMARY – SOUTH SHORE 1 1 Peak winds in the South Shore region were below forecast but did reach warning levels during the event. Areas nearer to Metro were closer to the extent of the 100 km/h wind field and likely experienced higher winds than those recorded at the Yarmouth station. Tree contacts and adverse weather were the leading outage causes. Outage Summary: Customers Impacted: 59,459 Customer hours of interruption: 635,356 Full Restoration*: 351.2 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 28.49 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start South Shore % Within 6 Hrs 49.99% Within 12 Hrs 51.88% Within 24 Hrs 58.28% Within 48 Hrs 83.48% 100% Adverse Weather Cause of Outage (CHI) Wind 1% 23% 2% 73% Cause of Outages (CHI) Loss of Supply Tree Contacts Lightning Adverse Weather 1 2 SECTION 4: ZONE IMPACT SUMMARY – SOUTH SHORE TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) South Shore 9/24/2022 01:33 Yarmouth 10 50 74 330 Adverse Weather Wind High winds caused trees to land on primary line, bringing down the line. 210 157.44 South Shore 9/24/2022 01:33 Yarmouth 10 50 74 330 Tree Contacts Falling Trees High winds caused a tree to land on the line, opening a transformer fuse. 1 136.78 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction Cause Sub-Cause Description Customers Impacted Duration (Hours) South Shore 9/24/2022 02:02 Yarmouth 10 50 81 330 Tree Contacts Broken Branch High winds caused trees to damage conductor and tear down poles, opening the recloser. 1987 54.2 South Shore 9/24/2022 07:25 Yarmouth 10 50 81 330 Tree Contacts Falling Trees High winds caused trees to land on the primary line, opening the recloser. 1923 3.53 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE IMPACT SUMMARY – NORTHERN 1 3 Peak winds recorded at the representative station for the Northern region were below forecast but recorded peak gusts were above warning levels. However, the representative station for this region is located inland and likely did not experience the extreme winds noted along the Northumberland Strait**. Wind and tree contacts with power lines had the largest impact in this region. Outage Summary: Customers Impacted: 41,974 Customer hours of interruption: 2,391,604 Full Restoration*: 352.9 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 117.28 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start Northern % Within 6 Hrs 5.06% Within 12 Hrs 6.79% Within 24 Hrs 14.80% Within 48 Hrs 24.77% 100% Adverse Weather Cause of Outage (CHI) Wind 5% 33% 1% 61% Cause of Outages (CHI)*** Loss of Supply Tree Contacts Failed/Damaged Equipment Adverse Weather **Stations at Caribou Pt., Charlottetown, and Moncton all recorded gusts above the Northern Station indicating that coastal areas of the region were harder hit than the representative station indicates. ***Failed/Damaged Equipment leading to outages during this event were influenced by the acute effects of the prevailing weather conditions leading to premature failure. 1 4 SECTION 4: ZONE IMPACT SUMMARY – NORTHERN TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Northern 9/24/2022 01:26 Nappan/D ebert 10 57 78 350 Tree Contacts Falling Trees High winds caused trees to land on the line, bringing down the customer's line between poles and to the house. 2 327.34 Northern 9/24/2022 01:26 Nappan/D ebert 10 57 78 350 Adverse Weather Wind High winds caused trees to land on customer's serviceline. 2 327.31 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction Cause Sub-Cause Description Customers Impacted Duration (Hours) Northern 9/23/2022 23:27 Nappan/ Debert 10 46 61 360 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the recloser. 2457 76.81 Northern 9/24/2022 01:50 Nappan/ Debert 10 57 78 350 Adverse Weather Wind High winds caused trees to damage conductor and tear down poles, opening the recloser 2122 14.56 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE IMPACT SUMMARY – NORTHEAST 1 5 Winds in the Northeast region exceeded 130 km/h during the event. Some other stations in this region recorded even higher gusts. 13 consecutive hours of gusts over 100 km/h were observed. Adverse Weather was the largest single contributor to customer impact, which also includes contact from trees. A further third of outages were due to tree contacts. Outage Summary: Customers Impacted: 127,683 Customer hours of interruption: 9,035,083 Full Restoration*: 403.5 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 148.38 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start Northeast % Within 6 Hrs 0.93% Within 12 Hrs 3.55% Within 24 Hrs 8.97% Within 48 Hrs 18.45% 100% Adverse Weather Cause of Outage (CHI) Wind 1% 10% 37% 3% 49% Cause of Outages (CHI)** Unknown Loss of Supply Tree Contacts Failed/Damaged Equipment Adverse Weather **Failed/Damaged Equipment leading to outages during this event were also influenced by the acute effects of the prevailing weather conditions leading to premature failure. 1 6 SECTION 4: ZONE IMPACT SUMMARY – NORTHEAST TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Northeast 9/24/2022 00:40 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to land on the line, bringing down the customer's line between poles and to the house. 1 397.35 Northeast 9/24/2022 00:09 Caribou Pt. 13 69 89 360 Tree Contacts Falling Trees High winds caused trees to land on the line, bringing down the customer's lineto the house. 3 396.36 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Northeast 9/23/2022 23:20 Caribou Pt. 12 61 82 10 Adverse Weather Wind High winds caused trees to land on primary lines, breaking poles and bringing down lines between poles. 2663 93.51 Northeast 9/24/2022 00:33 Caribou Pt. 12 61 82 10 Adverse Weather Wind High winds caused trees to land on primary lines, breaking poles near the substation. Protection device was opened as a result. 2370 91.71 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE SUMMARY IMPACT SUMMARY – METRO 1 7 Peak gusts in Metro were below forecast but reached over 110km/h during the event. Gusts approaching 125 km/h were recorded at other stations in the region. Adverse weather and tree contacts were the leading causes of outages in the region. Outage Summary: Customers Impacted: 331,481 Customer hours of interruption: 9,027,322 Full Restoration*: 374.1 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 68.86 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start Metro % Within 6 Hrs 15.47% Within 12 Hrs 30.20% Within 24 Hrs 44.11% Within 48 Hrs 67.92% 100% Adverse Weather Cause of Outage (CHI) Wind 1% 28% 3% 68% Cause of Outages (CHI)** Loss of Supply Tree Contacts Failed/Damaged Equipment Adverse Weather **Failed/Damaged Equipment leading to outages during this event were influenced by the acute effects of the prevailing weather conditions leading to premature failure. 1 8 SECTION 4: ZONE IMPACT SUMMARY – METRO TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Metro 9/23/2022 23:18 Halifax Airport 10 48 80 350 Adverse Weather Wind High winds caused trees to land on primary line, opening the switch. 6 323.36 Metro 9/23/2022 23:26 Halifax Airport 10 48 80 350 Tree Contacts Falling Trees High winds caused a tree to land on the lineto customer's house. 1 250.22 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Metro 9/24/2022 04:29 Halifax Airport 10 80 111 310 Adverse Weather Wind High winds and extreme gusts caused a tree to land on primary line, opening the recloser. 5298 16.74 Metro 9/29/2022 14:23 Halifax Airport 18 6 111 330 Adverse Weather Wind Emergency repairs to a damaged cutout due to extreme winds and gusts in days preceding. 4556 0.25 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE SUMMARY IMPACT SUMMARY – EASTERN SHORE 1 9 Peak winds along the Eastern Shore were above both forecast and warning levels, reaching a peak of 150km/h and sustained winds over 125 km/h. This region recorded 10 hours of gusts above 100 km/h. Adverse Weather and Tree Contacts were the cause of nearly all outage impacts. Outage Summary: Customers Impacted: 7,311 Customer hours of interruption: 599,697 Full Restoration*: 345.8 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 125.27 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start Eastern Shore% Within 6 Hrs 0.00% Within 12 Hrs 20.01% Within 24 Hrs 20.01% Within 48 Hrs 20.11% 100% Adverse Weather Cause of Outage (CHI) Wind Wet Snow Ice Flood 2% 46% 52% Cause of Outages (CHI) Loss of Supply Tree Contacts Adverse Weather 2 0 SECTION 4: ZONE IMPACT SUMMARY – EASTERN SHORE TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Eastern Shore 9/24/2022 02:30 Beaver Island 13 109 150 340 Tree Contacts Falling Trees Extreme winds and gusts caused a tree to land on the service line to customer's house. 1 326.52 Eastern Shore 9/24/2022 02:30 Beaver Island 13 109 150 340 Tree Contacts Falling Trees Extreme winds and gusts caused trees to land on the primary line, opening the fuse. 3 325.25 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Eastern Shore 9/24/2022 01:00 Beaver Island 12 121 150 350 Adverse Weather Wind Extreme winds and gusts caused trees to land on the primary lines, opening the protection device at the substation. 1409 17.81 Eastern Shore 9/23/2022 22:55 Beaver Island 13 93 122 20 Adverse Weather Wind High winds and extreme gusts caused trees to land on the primary lines, opening the recloser. 930 69.86 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON WEST 2 1 Observed winds in this region were above both forecast and warning levels (16 hours above 80 km/h) during the event reaching a peak gust of 139 km/h. Adverse Weather was the cause of two-thirds of outage impacts in the region with the balance resulting from tree contacts. Outage Summary: Customers Impacted: 4,273 Customer hours of interruption: 78,834 Full Restoration*: 358.3 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of restoration, rather than the start of their individual outage. Average restoration time for this region was 40.51 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start CB West % Within 6 Hrs 27.29% Within 12 Hrs 42.08% Within 24 Hrs 57.43% Within 48 Hrs 84.25% 100% Adverse Weather Cause of Outage (CHI) Wind 32% 68% Cause of Outages (CHI) Tree Contacts Adverse Weather 2 2 SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON WEST TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Cape Breton West 9/24/2022 11:20 Gr. Étang 13 65 139 210 Tree Contacts Falling Trees High winds and extreme gusts caused trees to land on primary line, opening the transformer fuse. 1 120.65 Cape Breton West 9/25/2022 18:22 Gr. Étang 11 83 139 260 Tree Contacts Falling Trees High winds and extreme gusts caused trees to land on customer’s serviceline. 1 116.59 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Cape Breton West 9/24/2022 01:11 Gr. Étang 15 65 87 10 Tree Contacts Falling Trees High winds caused trees to land on the primary line, opening the transformer fuse. 963 96.18 Cape Breton West 9/24/2022 01:11 Gr. Étang 15 65 87 10 Tree Contacts Falling Trees High winds caused trees to damage conductor and tear down poles, opening the recloser. 904 46.23 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON EAST 2 3 Observed winds in CB East region were slightly above forecast and significantly above warning levels. Peak winds recorded in Sydney reached 141 km/h including 6 consecutive hours of gusts above 120 km/h. Adverse weather and tree contacts were the leading causes of outages in this region. Outage Summary: Customers Impacted: 122,404 Customer hours of interruption: 8,311,389 Full Restoration*: 399.1 Hours *elapsed time from first outage event to restoration of last event This table represents the percentage of customers restored within 6, 12, 24, or 48 hours of the start of the storm, rather than the start of their individual outage. Average restoration time for this region was 99.26 hours. During the initial 24 hours of the storm, restoration was limited while crews were stood down due to extreme winds. Customers Restored within X hours of Restoration Start CB East % Within 6 Hrs 5.44% Within 12 Hrs 8.07% Within 24 Hrs 12.59% Within 48 Hrs 19.86% 100% Adverse Weather Cause of Outage (CHI) Wind 5% 28% 7% 60% Cause of Outages (CHI)** Loss of Supply Tree Contacts Failed/Damaged Equipment Adverse Weather **Failed/Damaged Equipment leading to outages during this event were also influenced by the acute effects of the prevailing weather conditions leading to premature failure. 2 4 SECTION 4: ZONE IMPACT SUMMARY – CAPE BRETON EAST TOP TWO EVENTS BY DURATION & CUSTOMER IMPACT Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Cape Breton East 9/24/2022 01:54 Sydney Airport 19 67 94 100 Tree Contacts Falling Trees High winds caused trees to land on the primary lines, opening the transformer fuse. 2 333.44 Cape Breton East 9/24/2022 01:54 Sydney Airport 19 67 94 100 Tree Contacts Falling Trees High winds caused trees to land on the primary lines, bringing down the line. 1 333.41 Zone Date/ Time Weather Station Temp (°C) Wind (km/h) Max Wind Gust (km/h) Direction (Degrees) Cause Sub-Cause Description Customers Impacted Duration (Hours) Cape Breton East 9/24/2022 02:22 Sydney Airport 18 72 122 110 Adverse Weather Wind High winds and extreme gusts caused extensive damage to all feeders from 11S substation, ultimately opening the substation recloser. 5565 225.07 Cape Breton East 9/24/2022 01:16 Sydney Airport 19 67 94 100 Tree Contacts Falling Trees High winds caused trees to contact the primary line, opening the recloser. 1943 64.78 Duration Customer Impact Large trees, often from outside cleared rights of way were uprooted or snapped, tearing down power line infrastructure. NS Power invests on average $20 - 25 million each year in tree trimming and clearing rights of way of trees. CEA DEFINITIONS 2 5 CI = Customer Interruptions Total number of customers without power CHI = Customer Hours of Interruption Combination of customers and duration SAIFI = Average Outage Frequency Customer interruptions / # of customers SAIDI = Average Outage Duration Customer hours of interruption / # of customers CAIDI = Average Outage Duration (for those interrupted) Customer hours of interruption / # of customer interruptions Adverse environment In te rru p tio n s d u e to e q u ip me n t b e in g s u b je c te d to ab n o rmal e n viro n me n tal c o n d itio n s (e.g. Salt spray, contamination, humidity, corrosion, vibration, fire, or flooding) Adverse weather Inte rruptions re s ulting from w e athe r c onditions ( e .g. Rain, ic e s torms , s now , w inds , extreme ambient temperatures, freezing fog, or frost) Defective equipment Inte rruptions re s ulting from e quipme nt failure s Foreign interference Inte rruptions due to e xte rnal c ontac ts be yond the c ontrol of the utility ( e .g. Birds , animals, vehicles, dig-ins , or othe r fore ign obje c ts ) Human element Inte rruptions due to e rrors of utility s taff in c ons truc tion, mainte nanc e , or ope rations Lightning Inte rruptions due to lightning s trike on e ne rgiz e d c irc uits Loss of supply Inte rruptions due to proble m in the bulk e le c tric ity s ys te m ( trans mis s ion) Scheduled outage Interruptions due to the planned disconnection for construction or maintenance purposes Tree contacts Interruptions caused by trees or tree limbs contacting energized circuits Unknown/other Inte rruptions w ith no appare nt c aus e or re as on ide ntifie d that c ould have c ontribute d to the outage