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DATE: |
June 9, 2005 |
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TO: |
Director, Division of the Commission Clerk & Administrative Services (Bayó) |
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FROM: |
Division of Economic Regulation (Breman, Lee) Office of the General Counsel (C. Keating) |
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RE: |
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AGENDA: |
06/21/05 – Regular Agenda – Proposed Agency Action – Interested Persons May Participate |
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COMMISSIONERS ASSIGNED: |
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PREHEARING OFFICER: |
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SPECIAL INSTRUCTIONS: |
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FILE NAME AND LOCATION: |
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Rule 25-6.0455, Florida Administrative Code, requires each investor-owned electric utility to file an Annual Distribution Service Reliability Report containing data that this Commission uses to assess changes in distribution reliability. Under subsection (2) of the rule, a utility may exclude specified outage events such as a storm named by the National Hurricane Center, a tornado recorded by the National Weather Service, ice on lines, and an extreme weather event causing activation of the county emergency operations center. In addition, under subsection (3), a utility may petition this Commission to exclude an outage event not specifically enumerated in subsection (2). However, the utility must “demonstrate that the outage event was not within the utility’s control, and that the utility could not reasonably have prevented the outage.” Rule 25-6.0455(3), Florida Administrative Code.
On December 7, 2004, Tampa Electric Company (“TECO”) filed a request for exclusion of outage events associated with weather systems on April 11-12, 2004, and on June 13, 24, and 26, 2004, pursuant to Rule 25-6.0455(3), Florida Administrative Code. In conjunction with its request for exclusion, TECO filed a petition seeking a variance or waiver from that portion of Rule 25-6.0455(3), which provides that the request must be filed within 30 days of the outage event for which an exclusion is requested.
TECO’s rule waiver petition was granted by the Commission at the February 1, 2005, Agenda Conference. At that Agenda Conference, TECO orally withdrew its request to exclude outage events on June 13, 24, and 26, 2004. TECO did not withdraw its request for an exclusion of outage events on April 11-12, 2004, because (1) TECO believes the same weather system impacted TECO, Florida Power & Light Company (“FPL”) and Progress Energy Florida, Inc., (“PEFI”); and (2) the Commission granted FPL’s and PEFI’s exclusion requests.[1],[2]
This recommendation addresses TECO’s request to exclude the April 2004 outage events. The Commission has jurisdiction over this matter pursuant to Chapter 366, Florida Statutes, including Section 366.04, 366.041, 366.05, Florida Statutes.
Issue 1:
Should the Commission approve TECO's petition to exclude from its 2004 Annual Distribution Service Reliability Report 174 outage events that occurred due to a weather event on April 11-12, 2004?
Recommendation:
No. TECO has not demonstrated that the outages on April 11-12, 2004, were not within its control and that it could not reasonably have prevented the outages because: (1) sustained wind speeds in TECO’s service area did not exceed industry construction standards; (2) TECO maintains control over its tree-to-power line clearance practices and can adjust those practices if it believes wind related outages are excessive; (3) TECO maintains control over its lightning protection practices and can adjust those practices if it believes lightning related outages are excessive; and (4) TECO has not demonstrated that the high wind speeds that occurred in FPL’s and PEFI’s respective service areas also occurred in TECO’s service area on April 11-12, 2004. However, If the Commission approves the petition, TECO should show the effects of including and excluding the wind and lightning caused outage events in a revised 2004 Annual Distribution Service Reliability Report for comparability purposes. (Breman, Lee)
Staff Analysis:
Summary of TECO’s Petition
TECO’s petition, at paragraph 6, asserts that the weather event of April 11 and 12 that impacted TECO was the same weather phenomenon described in detail in the requests for exclusions filed by FPL and PEFI. In Exhibit A to its petition, TECO provides lightning strike data from 6:00 p.m. on April 11, 2004, through 9:00 a.m. on April 12, 2004. TECO states that very heavy rains, strong wind, and extensive lightning affected its service area resulting in 174 outage events affecting a total of 18,829 customers. The System Average Interruption Duration Index (“SAIDI”) is a measurement of how long the average customer was without electric service. TECO’s five year daily average SAIDI for April is 0.09 minutes. The 174 outage events result in a SAIDI of 3.05 minutes for the 24-hour period on April 11-12, 2004. TECO’s petition did not include any wind data related to the April 2004 weather event.
Subsequent to the February 1, 2005, Agenda Conference, staff had several informal discussions with TECO staff focusing on apparent differences between TECO’s petition, which was based on how much lightning occurred, and the petitions of PEFI and FPL, which were based on a non-thunderstorm high wind event. Staff also pointed out that the National Weather Service (“NWS”) does not use lightning as a criteria for defining severe weather. A severe thunderstorm is any storm that produces a tornado, or damaging winds of at least 50 knots (58 mph), or hail three quarters of an inch in diameter or greater.[3] Staff also noted that there is no standard for utility construction regarding lightning while there is a construction standard regarding wind speed.
On April 1, 2005, TECO filed supplemental information provided by a consultant, Mr. Robert Mullenax, a meteorologist with ImpactWeather, Inc. The supplemental filing is Attachment 1 to this recommendation. In the letter, Mr. Mullenax discusses the various characteristics of the wind events of April 11-12, 2004. Mr. Mullenax states the highest wind speed recorded within TECO’s service area was 30 mph and that it was likely there were pockets of much stronger winds. No specific wind speed greater than 30 mph is noted within Mr. Mullenax’s letter.
Construction Standards
TECO’s construction standard for wind is based on compliance with the National Electric Safety Code, Section 24, “Grades of Construction.” The construction standard is equivalent to designing for a sustained 60 mph wind. Sustained winds exceeding TECO’s construction standard of 60 mph could result in outages caused by winds blowing over poles and stripping poles of the attached hardware.
Attachment 2 to this recommendation is a copy of TECO’s response to the first question of a staff informal data request in Docket No. 050058-EI, In Re: Request of Tampa Electric Company to Exclude Outage Event on December 26, 2004 from its Annual Distribution Service Reliability Report. In its response, TECO lists information for all wind events in excess of 40 mph that it could document within its service area since January 1, 2000. TECO’s response does not show that a wind event exceeding 40 mph occurred on April 11-12, 2004. Further, all events listed in Attachment 2 have been included in TECO’s Annual Distribution Service Reliability Reports.
On April 11-12, 2004, the peak wind speed of 30 mph within TECO’s service area did not exceed TECO’s construction standard of 60 mph. TECO provided no evidence of pole and fixture failure due to sustained high wind speeds. Rather, the outage events on April 11-12, 2004, appear to be related to trees contacting power lines and other thunderstorm causes such as lightning.
Tree-to-Power Line Clearances
Utilities may implement changes to their vegetation maintenance programs as they deem appropriate. All other things being equal, the same level of wind speed can cause more outages if a utility elects to allow less clearance between trees and power lines. The converse is also true. Thus, the utilities exercise control over wind/tree related outages.
TECO’s tree-to-power line clearance practice is currently based on various performance factors such as the number of outages and tree growth rates. TECO’s practice can be characterized as performance-based because TECO does not have a specific trim cycle. The amount of tree-to-power line clearence at any given time and place is a result of how aggressive TECO is in maintaining the maximum achievable tree-to-power line clearance. Thus, tree-to-power line clearances and the resulting number of outages are matters TECO already incorporates into its decisions. If the number of outages is excessive, based on TECO’s internal review, then TECO may elect to implement a more aggressive line clearance practice. On the other hand, TECO may elect to keep its practice the same or relax its practice if the number of resulting outages is not excessive.
TECO’s Annual Distribution Service Reliability Reports include the number of outages caused by all types of vegetation without separately listing the tree caused outages. TECO’s 2002, 2003, and 2004 reports indicate that the number of vegetation-caused outages were 1,668, 2,003 and 1,880 respectively. Vegetation-caused outages as a percentage of total outages for the same period were 14%, 16%, and 17%, respectively. This increasing trend does not appear to support TECO’s claim that wind/tree related outages are beyond its control because of the increase in vegetation caused outages. The 2004 data include all vegetation-caused outages that TECO seeks to exclude.
Staff believes that TECO’s implementation of vegetation management practices demonstrates that TECO exercises control over the number of outages resulting from winds that typically occur within its service area. If TECO believes the outages of April 11-12, 2004, were excessive in light of the wind speeds recorded for that day, then TECO can revisit its vegetation management practices.
Lightning Protection
As previously mentioned, there is no industry standard for excessive lightning. In absence of an industry standard, each utility can change their respective lightning protection programs as they deem appropriate. All things being equal, the same level of lightning can cause more outages if a utility elects to implement less protection. The converse is also true. Thus, utilities exercise control over lightning caused outage events.
TECO’s Annual Distribution Service Reliability Reports include the number of outages caused by lightning. TECO’s 2002, 2003, and 2004 reports indicate the number of lightning-caused outages and the number of such outages as a percentage of total outages were 2,148 (18%), 2,481 (20%), and 2,283 (21%), respectively. This increasing trend does not appear to support TECO’s claim that lightning-related outages are beyond its control because of the increase in lighting caused outages. The 2004 data include all lighting caused outages that TECO seeks to exclude.
Staff believes TECO’s implementation of lightning protection demonstrates that TECO exercises control over the number of outages resulting from lightning that typically occur within its service area. If TECO believes the outages of April 11-12, 2004, were excessive in light of the lightning strikes recorded for that day, then TECO can revisit its lightning protection practices.
Conclusion
Staff believes TECO has not demonstrated that the outage events on April 11-12, 2004, were not within its control and that it could not have reasonably prevented the outages because: (1) sustained wind speeds in TECO’s service area did not exceed industry construction standards; (2) TECO maintains control over its tree-to-power line clearance practices and can adjust those practices if it believes wind related outages are excessive; (3) TECO maintains control over its lightning protection practices and can adjust those practices if it believes lightning related outages are excessive; and (4) TECO has not demonstrated that the high wind speeds that occurred in FPL’s and PEFI’s respective service areas also occurred in TECO’s service area on April 11-12, 2004. Therefore, TECO has not made the showing required by Rule 25-6.0455(3), and the petition should be denied.
If the Commission approves the petition, TECO should show the effects of including and excluding the wind and lightning caused outage events in a revised 2004 Annual Distribution Service Reliability Report for comparability purposes.
Issue 2:
Should this docket be closed?
Recommendation:
Yes, this docket should be closed upon issuance of a Consummating Order unless a person whose substantial interests are affected by the Commission’s decision files a protest within 21 days of the issuance of the proposed agency action. (C. Keating)
Staff Analysis:
If no timely protest to the proposed agency action is filed within 21 days, this docket should be closed upon issuance of a Consummating Order.
