2013 December Ice Storm

Transcription

1 2013 December Ice Storm

2 The 2013 December ice storm caused major damage to the Lansing Board of Water & Light (BWL) electric distribution system and had a devastating effect on many BWL customers. We realize and are sorry that many of our customers suffered during the most important holiday of the year when they expected to be celebrating with family and friends. We also realize our customers had difficulty reporting their outages and getting information on restoration times which aggravated this suffering, for which we apologize.

3 The impact of this storm on the BWL s distribution system was unprecedented and there has not been a storm with this impact ever reported by Michigan utilities. Many customers have asked questions regarding the BWL s electric reliability and the impact of the December ice storm. We have prepared the following frequently asked questions to help understand the BWL s restoration effort.

4 How is electric reliability Measured? In the U.S., three indices are commonly used to measure electric reliability. 1. System Average Interruption Duration Index (SAIDI). This measures total outage minutes experienced by all customers of a utility divided by the total number of customers served by a utility, recognizing that not all customers experience an outage. 2. Customer Average Interruption Duration Index (CAIDI). This measures the average outage duration for those customers who do experience an outage. 3. System Average Interruption Frequency Index (SAIFI). This measures the average number of interruptions per customer.

5 How is electric reliability Measured? (continued) The Michigan Public Service Commission (PSC) has required the regulated utilities under its jurisdiction to annually report their reliability as measured by these indices. (SAIDI, CAIDI & SAIFI) As Michigan s largest municipal utility, the BWL is frequently compared to Michigan s large investor owned utilities such as Detroit Edison (now DTE Energy) and Consumers Energy. The following pages show how the BWL s electric reliability indices compare to DTE and Consumers Energy for the past several years.

6 1200 Average Interruption Duration In Minutes for All Customers (SAIDI) Minutes Consumers Energy Detroit Edison LBWL Includes All Events

7 Average Outage Duration Minutes for those Customers Experiencing Interruption (CAIDI) Minutes Consumers Eenrgy Detroit Edison LBWL Includes all events

8 Average Number of Interruptions Per Number of Interruptions Customer (SAIFI) Consumes Eenrgy Detroit Edison LBWL Includes all Events

9 If the BWL is a reliable electric provider, why did it take so long to restore electric service to its customers following the December ice storm? This storm is defined as a catastrophic storm by the Michigan Public Service Commission. The MPSC defines a catastrophic storm as one that results in 10% or more of a utility s customers experiencing outages or a storm for which a unit of government has declared an emergency. The MPSC requires utilities that it regulates to file annual reports on service quality. Included in these annual filings is information on the impact of catastrophic storms. The following slide records the severity of MPSC designated catastrophic storms, as measured by the percentage of customer outages experienced by the major utilities, since the MPSC has required data to be reported. The highest outage rate experienced prior to December s ice storm was 26% in The BWL experienced a loss of 40% of its customers in the December storm. Simply stated, there have been no storms of comparable severity expereienced by a Michigan utility.

10 Percentage of Customers Out of Service Catastrophic Storms Percentage of Customers Consumers Energy Consumers Energy2 Consumers Energy3 Detroit Edison Detroit Edison2 LBWL Year

11 Do storms with the impact of the December ice storm occur elsewhere? Storms with the severity of December s ice storm do occur elsewhere in the U.S. and are usually associated with tropical storms or low category hurricanes impacting costal states. Or widespread ice storms that impact an entire utility service area. These high impact storms tend to be unique and their impacts depend on the design of a utility s transmission/distribution system, the geography of a service territory, age of infrastructure, and type of storm. Ice storms and snow storms (especially fall snow storms when leaves are still on trees) can be particularly difficult for restoration efforts since a high proportion of individual customer outages occur during these events. There are no uniform metrics or reporting requirements for major storm events in the U.S. but high impact, widespread ice storms result in extended customers outages wherever they occur in the U.S.

12 Major Winter Storm Related Outages 2011 New Jersey Jersey Central Power & Light 39% of JCP&L s customers lost power Full restoration required 10 days Public Service Electric & Gas 29% of PSE&G s customers lost power Full restoration required 9 days

13 Major Winter Storm Related Outages 2008 New Hampshire Public Service of New Hampshire 65% of PSNH s customers lost power Full restoration required 14 days Unitil 51% of Unitil s customers lost power Full restoration required 10 days New Hampshire Electric Cooperative 61% of PHEC s customers lost power Full restoration required 14 days National Grid 60% of National Grid s customers lost power Full restoration required 11 days

14 Are New Jersey s and New Hampshire s restoration efforts typical for major ice storms? New Jersey s and New Hampshire s restoration experiences are not unusual. While some utilities experiencing ice storms have restored all services in less time, others have required more time than these examples. How long did it take the BWL to restore power to its customers? Ten days.

15 Why does it take so long to restore power to all customers following a major storm? Storms that result in a high percentage of customers outages have distinctive restoration patterns. These patterns are shown in restoration curves. The curves show the percentage of customers experiencing outages during a storm who are returned to service following the storm. The following page shows state restoration curves following a severe weather event in the Ohio Valley and Mid-Atlantic states during the summer of It is important to note that restoration of the last 10% of customers who have experienced an outage during a severe event requires almost the same amount of time as restoration to the first 90% of customers restored. The extended restoration time for the last 10% of customers results because customers must be restored individually or in small groups, which takes more time.

16 Percent Restored Since First Outage Reported Restoration Curves for 100 Catastrophic Events Indiana Maryland New Jersey Ohio Virginia West Virginia Days Since First Outage Reported

17 The following page shows the BWL s December ice storm restoration curve which fits the typical restoration curve experienced by utilities throughout the U.S.

18 Percent Restored Since First Outage Reported Restoration Curves for 100 Catastrophic Events Indiana Maryland New Jersey Ohio Virginia West Virginia LBWL Days Since First Outage Reported

19 Thank you for taking the time to read this presentation. If you have any further questions, please contact: Name: George Stojic Phone: (517)