PUBLIC UTILITIES ADVISORY BOARD AGENDA ITEM
ACTION REQUESTED:
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Receive Analysis of System Performance Metrics & Data Anomalies (Jan- July/2026)
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DEPARTMENT: Electric Utility
SUBMITTED BY: Electric Utility
BOARD/COMMISSION REVIEW:
N/A
Purpose
The purpose of this memorandum is to summarize key operational metrics, highlight critical performance deviations, and identify data anomalies observed in the Electric Utility dashboards for the 2026 calendar year.
BACKGROUND:
Staff reviewed data from four primary dashboards:
1. SAIDI (System Average Interruption Duration Index): Internal reliability report (July 31, 2026).
2. Electric Consumption Report: Historical usage through Dec 2025.
3. Naperville Renewable Energy: 2026 Summary Snapshot.
4. IMEA Energy Efficiency Rebates: 2026 Summary Snapshot.
Discussion
1. Increase in System Reliability (SAIDI) The most concerning metric in the dataset is the System Average Interruption Duration Index (SAIDI).
● Observation: The 12-month average SAIDI 42.29 minutes per customer, a 173.5% increase compared to the previous year (15.46 minutes).
● Trend: The historical graph shows a steady incline going into summer of 2026.
2.Electric Consumption Report
● Observation: Total electric consumption for 2025 through July was 753,138 MWh.
● Trend: This represents a 0.53% decrease through July 2026 from 2025 (749,125 MWh).
● Demand: Despite the slight decrease in consumption, the City Electric demand (320 MW) in 2025 was lower from 2026 (332 MW). This represents a 3.8% increase.
3.Naperville Renewable Energy
Participation in the REP has steadily increased over the years, supported by a change made in 2024 which requires incentive recipients to remain in the program for a minimum of five years. This requirement ensures that program membership and revenue remain stable.
● Observation: In 2026, the three most popular incentive types were Residential Solar, Attic Insulation, and Window Replacement. The budgeted $280,000 for the program in 2026, As of 06/30/2026 $280,000 has been rebated to customers.
4.IMEA Non- Residential Energy Efficiency Rebates
● 2026 Summary: 41 Cumulative 2026 Awards as 27 more project awards through 07/31/26 (Was for 2025: 28)
● Positive Indicator: 941,287 Cumulative 2026 kWh Annual Estimated kWh savings through 07/31/26. $248,705 Cumulative 2026 $ Awarded as of 07/31/2026.
5.ComEd Comparison
● 2026 Residential Rate Comparison Data: Naperville Staff compares total residential electric bills for an average household that utilizes 844kWh of energy per month.
● Future Reports: Monthly comparisons will be provided to PUAB going forward.
○ Price to Compare: ComEd Price to compare along with additional information can be found at the following location:
<https://plugin.illinois.gov/understanding-the-price-to-compare/price-to-compare-comed.html>
○ ComEd Bill Line Items: All charges from a sample ComEd Residential Electric Bill have been included have been included except for distribution specific charges.
IMEA: IMEA’s all in cost to the City of Naperville for the specified month was utilized.
Recommendations:
Recommend acceptance of performance metric dashboard summaries.