PUBLIC UTILITIES ADVISORY BOARD AGENDA ITEM
ACTION REQUESTED:
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Receive Analysis of System Performance Metrics & Data Anomalies (Jan- Feb/2026)
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DEPARTMENT: Electric Utility
SUBMITTED BY: Brian Groth, Electric Utility Director
BOARD/COMMISSION REVIEW:
N/A
BACKGROUND:
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.
1. SAIDI (System Average Interruption Duration Index): Internal reliability report (Feb 28, 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.
5. ComEd Comparison
6. Market, IMEA, IPA, ComEd Energy Cost Comparison
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 declined to 21.06 minutes per customer, an 13.61% decrease compared to the previous year (24.38 minutes).
● Trend: The historical graph shows a steady decline going into 2026.
2.Electric Consumption Report
● Observation: Total electric consumption for 2025 was 1,288,334 MWh.
● Trend: This represents a 0.88% increase from 2024 (1,277,056 MWh).
● Demand: Despite the slight increase in consumption, the City Electric demand (320 MW) was lower from 2024 (347 MW). This represents a 7.8% decrease.
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 02/28/2026 $103,910 has been rebated to customers.
4.IMEA Non- Residential Energy Efficiency Rebates
● 2026 Summary: 9 Cumulative 2026 Awards as 9 more project awards through 02/28/26 (Was for 2025: 28)
● Positive Indicator: 537,096 Cumulative 2026 kWh Annual Estimated kWh savings through 02/28/26. $76,091.65 Cumulative 2026 $ Awarded as of 02/28/2026.
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.
6.Market, IMEA, IPA, ComEd Energy Cost Comparison
● PJM Planning Year 2025 - 2026: Cost comparisons of various energy sources are provided along with a matrix of what is included in the average price shown. Data is provided for the 2025-2026 PJM planning year which began on June 1, 2025, and will continue through May 31, 2026.
○ 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>
○ Market Energy/Capacity/Transmission: PJM day ahead market prices combined with total city hourly load, market capacity and market transmission costs have been averaged both in a weighted and non-weighted fashion. The City’s Transmission and Capacity obligations were used for the respective months’ analysis.
○ 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.