June 22, 2000

MEMORANDUM

To:  Stakeholders, Electric System Reliability Rulemaking: Docket - UE991168
From:  Electric System Reliability Rulemaking Team (Commission Staff)
Subject: First Discussion Draft of Possible Rules on Sustained Interruptions


Introduction

In September, 1999, the Commission began an investigation of electric system 
reliability, and whether to adopt a rule on reliability monitoring and 
reporting.  Commission Staff has held two workshops on the issue and has 
received comments.  Through the participation of stakeholders we have learned 
valuable information.  A recurring theme of commentors has been that staff 
should be more clear about what the Commission wants, and why.  Based on those 
comments, and on our research, Commission Staff has drafted a proposed rule for 
comment. 

Commission Staff has not yet decided to recommend that the Commissioners adopt 
a rule, nor has the content of a rule been determined.  If Staff recommends 
that the Commission adopt a rule, the CR-102 (Proposed Rule Making) process 
will offer additional opportunities for comment.

Draft Description

The draft addresses only sustained interruptions.  Commission and stakeholder 
concerns about power quality and momentary interruptions may be addressed in a 
future proceeding.

We have tried to address key utility concerns.  The draft allows for utility 
specific plans rather than a one-size-fits-all approach.  It emphasizes data 
reporting, and does not define standards.  As we learn more about reliability 
from the reports under the proposed rule, the Commission may decide whether 
standards should be established in the future.

The draft limits changes to current practices, and de-emphasizes comparable 
system-wide measures.  We believe that the draft represents a first-step toward 
addressing key customer concerns: 1) that areas of poor reliability are 
identified and improved; and 2) that customers learn of steps being taken to 
improve the reliability of their electric service.   

The draft uses the following general approach:

• Companies would file a plan with the Commission that says how the rule will 
be implemented.  The rule can  be implemented in stages, and in different ways;
• Companies would monitor reliability and file an annual report to the 
Commission; and
• Companies would provide reliability information to the Commission and 
customers on request.

The draft would require utilities to monitor sustained interruptions at, or 
near, the customer level.  This would ensure that pockets of poor reliability 
would not be hidden in average statistics.  This would allow the Commission to 
see reliability problem areas, and consider whether service is adequate for 
individual customers, given their circumstances and location.  Aggregating 
individual cases back to the circuit level would allow us to see the worst 
performing circuits—defined as those that have the most customers with the 
worst reliability.  While the Commission is interested in average system 
performance, allowing Commission Staff to focus on the areas of worst 
performance is a priority. 

At the beginning of this investigation, the Commission Staff did not expect 
that monitoring at the customer level  would be technically feasible for all 
three electric utilities.  Our current understanding is that, given reasonable 
time for implementation, companies could provide this information.  We would 
like to explore with stakeholders whether this level of monitoring is 
achievable, and how much it may cost.

If rules do not emphasize system-wide statistics, definitions for how to 
calculate indexes may become less important.  This draft includes industry 
standard definitions, a goal shared by both the Commission and the companies.  
It appears that use of industry standard definitions would mean that Companies 
would not need to make expensive changes to current in-house reporting 
practices.

This draft would allow Companies to implement the rule over time, in 
increments, and in different ways depending on the capabilities, preferences 
and geography of each company.  Each company would develop its own plan for 
implementing the rule, identify what will be reported to the Commission, and 
submit its plan without a requirement for formal approval of its contents.

The draft calls for Companies to deliver an annual reliability report to the 
Commission.  This report is the primary way staff will monitor system 
reliability.  Staff would like to explore with stakeholders the question of 
whether an annual report is sufficient, or whether monthly or quarterly reports 
would make more sense.

By focusing on areas with the poorest reliability, we can reduce the amount of 
information reported to the Commission.  The draft, for example, calls for 
utilities to provide charts with explanatory text to the Commission with most 
of the information only about problem areas.

The draft rule focuses on charts and explanatory text.  With the draft, we have 
attached sample  charts that provide some sense of what we are looking for in 
the annual reliability report.  

Chart 1: Interruptions and Hours of Interruption Over Time. 

This is one of two or three charts that would reflect full system data, to show 
the big picture of when the most interruptions occur and when they last the 
longest.

Chart 2: Customer Data Reported System Wide - The Number of Interruptions 
Experienced by Customers.  

This chart would also be built using data from the entire system.  It is 
designed to give us a sense of the levels of reliability experienced by 
customers.  An accompanying chart would show the same for duration. 

Chart 3: Looking at the Tail - Identifying Threshold Customers.  

This is a key chart that begins the process of focusing on the areas of poorest 
reliability —the “tail.”  Some level of reliability—a threshold—will be set by 
the utilities in their plan.

Chart 4: Different Threshold Criteria for Different Areas.  

Reliability may reasonably differ for geographic and other reasons.  Chart 4 
would show how the utility may differentiate one area from another to report 
different threshold levels.  For example, the threshold for reporting may be a 
higher number of interruptions in a high-cost area, while in a low-cost area 
the threshold for reporting might be a lower number of interruptions.

Charts 5 & 6: Location of Threshold Customers / Threshold Customers in the 
Current Year that Were Threshold Customers in the Previous Year.  

These charts are designed to show  the locations of customers who have 
experienced the lowest levels of reliability in a way that allows us to see 
whether certain areas represent large or chronic concerns.

Chart 7: Threshold Circuits & Interruption Data.  

This chart provides data to accompany the maps.  Company management and  
Commission Staff will be able to identify areas of greatest concern, determine 
whether they represent chronic problems, and explore reasons why the 
interruptions occurred.  Accompanying text would explain the Company’s plans to 
address problem areas.

We look forward to receiving written comments about this approach by July 14, 
2000, and oral comments at our July 21, 2000, workshop.


Attachments:

Notice of Opportunity to Comment & Notice of Workshop
1st Informal Draft Reliability Rules & Example Graphs