Statistical Update

ETSA Utilities’ Operational & Performance Data - December 2011 Quarter

The Australian Energy Regulator is responsible for the price regulation of electricity distribution services in South Australia.  However, the Commission is responsible for setting the distribution service standards to apply to ETSA Utilities in South Australia. Those standards are set out in the Service Standards Framework established under the Commission’s Electricity Distribution Code. The code prescribes various requirements in relation to quality and reliability of supply as well as customer service outcomes (telephone and written enquiry responsiveness).

Customer Service

Under the Service Standards Framework, ETSA Utilities is required to report on average response times to customer enquiries and provide advice on certain matters within specified timeframes on an annual basis. Those target timeframes, together with ETSA Utilities’ customer service performance are summarised for the December quarter 2011, in Table 1. It should be noted that the targets are annual performance targets.

Table 1 - Customer Service
Performance Measure Target Total Number
(Dec Qtr)
(Dec Qtr)
Respond to telephone calls 85% within 30 seconds 165,457         90%
Respond to written enquiries 95% within 5 business days         885         99%
Written explanation for
interruptions to supply
85% within 20 business days              1       100%
Planned interruptions At least 4 business days written notice         898         96%

Guaranteed Service Levels

Part B of the Electricity Distribution Code (the standard connection and supply contract between ETSA Utilities and customers) provides for a Guaranteed Service Level (GSL) regime. Under this regime, if ETSA Utilities breaches a GSL, that breach triggers a payment to the affected customer(s). The GSLs relate to the timeliness of certain actions by ETSA Utilities (e.g. repair of street lights that have gone out; restoration of supply after an interruption).

Those GSL customer service standards, together with ETSA Utilities’ performance as reported for the December 2011 quarter, are presented in Table 2.

Duration of supply interruptions, totalling $1,098,195 comprised 98.6% of the total GSL customer payments made in the December 2011quarter. There was a three-fold increase in the number of GSL payments and a four-fold increase in the value of duration outage payments during the December quarter compared to the September quarter.   Over half of those payments (53%, to the value of $577,200) were made to 1,560 customers who experienced supply interruptions greater than 24 hours.

The September 2011 quarterly performance update noted that the quarter was unremarkable, where GSL payments decreased significantly compared to the March 2011 quarter because there was less severe weather, and correspondingly, fewer power interruptions. However, the December 2011 quarter recorded a similar result to the March quarter, but the major differences being significantly fewer outages for December in the 12-15 hour band (586 compared to 4,728 in March) and the >24 hour band (1,560 compared to 3,154 in March).

Although the influence of severe weather directly affects network performance, the Commission is concerned about the duration of outages, particularly in the remote sections of the network in both the Central and Upper North & Eyre Peninsula regions. Access to properties to restore supply following excessive rainfall, is reported to be a major contributor to the protracted nature of some interruptions in those regions.

Table 2 - Guaranteed Service Levels performance and payments
Performance Measure Target Performance
(Dec Qtr)
GSL Payment
(Dec Qtr)
Timeliness of Appointments No more than 15 minutes late 100%  $        0
Promptness of Connection of New Supply Addresses Date agreed (or within 6 business   days) 99% $8,400
Timeliness of Street Light Repairs Major Metropolitan and Regional Areas - within 5 business days 98.5% $6,725
Country Areas - within 10 business days 98.5% $   125
Duration of Supply Interruptions Various 4,964 payments $1,098,195
Frequency of Supply Interruptions (Financial Year Only) Various (Annual) (Annual)

Network Reliability Performance

Part of the Commission’s regulatory focus for ETSA Utilities is to assess its reliability supply performance in accordance with the regulatory instruments that define the SA Electricity Distribution Service Standards Framework 2010 – 2015.

Reliability of electricity supply, as measured by supply interruptions, is a core aspect of network performance. Two of the key indicators of distribution network supply interruptions on customers are the duration of interruptions (System Average Interruption Duration Index, SAIDI) and the frequency of interruptions (System Average Interruption Frequency Index, SAIFI).

The Electricity Distribution Code specifies best endeavours SAIDI and SAIFI targets for ETSA Utilities in various geographic regions of the state. Table 3 below shows SAIDI and SAIFI performance (December quarter 2011) for the geographical regions.

Table 3 - Reliability Performance
Region SAIDI Performance
SAIFI Performance
(Number of Interruptions)
Dec Qtr YTD Target
Dec Qtr YTD
Adelaide Business Area (ABA) 25     0.71      1.32     0.25 0.011 0.015
Major Metropolitan Areas (MMA) 130    23.0    40.9     1.45 0.306 0.520
Central 260  141.6 179.8     1.8 0.464 0.757
Eastern Hills/Fleurieu Peninsula (EH&FP) 295    96.6 151.6     2.8 0.639 1.249
Upper North & Eyre Peninsula (UN&EP) 425  225.0 286.7     2.3 0.865 1.248
South East (SE) 295    61.5 103.2     2.5 0.348 0.844
Kangaroo Island (KI) 450    94.0 159.9    N/A N/A N/A
Total Network (TOTAL) 179    54.0    80.1  1.68 0.381 0.648

In contrast to the previous quarter, where less than 15% of the implied annual statewide target of 179 minutes had been expended, the results for the December quarter SAIDI has caused this to rise to nearly 45% of the annual target. Notwithstanding, on a state-wide basis, SAIDI performance appears to be on track to meet the annual target at the half-way point of the year.

Severe weather caused widespread interruptions in the Central (on 9 November) and Eastern Hills & Fleurieu, Upper North & Eyre Peninsula, Kangaroo Island and Central regions on 17 December. Two regions, Central (142 minutes) and Upper North & Eyre Peninsula (287 minutes), experienced the greatest impact from weather; 69% and 67% respectively of their annual SAIDI target has been expended which may affect the ability to achieve the annual target in the two regions.

The graph below shows the monthly SAIDI outcomes for the current and preceding quarters.

Figure 1 - SAIDI Performance July to December 2011

Mar12 SAIDI - Dec Qtr 11

The impact of severe weather on SAIDI is evident for the Central and Upper North & Eyre Peninsula regions. All regions, except those two, are on track to meet their respective SAIDI targets. The Kangaroo Island, South East and Major Metropolitan regions have expended about one-third of their annual target. Again, the Adelaide Business Area continues to perform well having expended only 5% of its annual target of 25 minutes.

The severe weather event in the Central region on 9 November contributed 76 minutes to the region’s SAIDI and had a strong influence on the state-wide performance that month, being the region with the second-largest number of customers. Extended restoration times (over 4 hours on average) were experienced in the Central, Upper North & Eyre Peninsula and Kangaroo Island regions during the December quarter.

Figure 2 – SAIFI Performance July 2011 to December 2011

Mar12 SAIFI Dec Qtr 11

Figure 2 shows a generally increasing trend in SAIFI performance during the December quarter. The Upper North & Eyre Peninsula region recorded the highest regional SAIFI of 0.87 average interruptions for the quarter followed by Eastern Hills & Fleurieu Peninsula region with 0.64 average interruptions. However, all regions are on track to achieve their annual targets with only the Eastern Hills & Fleurieu Peninsula region exceeding half of the annual target (54%) at the mid-point of the year.

The December quarter state-wide SAIFI of 0.381 average interruptions (23% of the annual target), was satisfactory. There is no applicable performance target for this measure for the Kangaroo Island region. However, the reported SAIFI, in conjunction with SAIDI, provides an important indication of restoration performance.

The Adelaide Business Area region annual SAIFI performance of 0.011 average interruptions (4% of the annual target) continues to be exceptional.