City of Naperville Electric Utility Rate Selection Guide
The City of Naperville Electric Utility (DPU-E) is a municipally owned electric utility serving about 63,700 customers in Naperville, IL. It offers first-party billing via eBill and 15-minute interval usage data through its in-house Empower portal, but has no Green Button, EDI, or public API; third-party access is manual under Illinois law 220 ILCS 5/16-122.
City of Naperville Electric Utility Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| Small Commercial (GS1) | Commercial | $41.77/mo + $0.11933/kWh (no demand) | Small businesses without significant metered demand. |
| Large Commercial (GS2) | Commercial | $130.00/mo + $0.05568/kWh + $22.25/kWd | Mid-to-large facilities with metered demand. |
| Extra Large Commercial (GS2) | Industrial | $130.00/mo + $0.05568/kWh + $22.25/kWd | High-load industrial/large commercial facilities. |
Market Overview
As a municipal utility, Naperville is locally owned and operated and is not part of Illinois's deregulated retail market. Rates are set by city ordinance (Title 8, Chapter 1, Article C) with wholesale supply via IMEA; there is no customer switching.
Need to pull your actual usage data to compare rates? See the City of Naperville Electric Utility Data Access Guide →
Current Rate Schedules
Naperville's 2026 electric rates are published by the utility following a 2024 rate study (rates set 2025-2027). C&I figures below are verified from the utility's published rate table. Large Commercial and above are on GS2: a $130.00 monthly customer charge, $0.05568/kWh energy, and a $22.25 per-kW (kWd) demand charge, plus a monthly Purchased Power Adjustment (PPA). Small Commercial (GS1) is $41.77/month and $0.11933/kWh with no demand charge.
Effective: January 1, 2026 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| Small Commercial (GS1) | commercial | Small commercial accounts (average ~1,865 kWh/month). | Monthly customer charge $41.77 plus $0.11933/kWh; no demand charge. Average monthly bill ~$264.32 (2026). Plus monthly PPA. | — |
| Large Commercial (GS2) | commercial | Large commercial accounts (example ~2,500 kWh, ~100 kWd). | Monthly customer charge $130.00, $0.05568/kWh, demand charge $22.25 per kWd. Example average monthly bill ~$2,494.20 (2026). Plus monthly PPA. | — |
| Very Large Commercial (GS2) | commercial | Very large commercial accounts (example ~50,000 kWh, ~225 kWd). | Monthly customer charge $130.00, $0.05568/kWh, demand charge $22.25 per kWd. Example average monthly bill ~$7,920.25 (2026). Plus monthly PPA. | — |
| Extra Large Commercial (GS2) | industrial | Extra large commercial/industrial accounts (example ~220,000 kWh, ~750 kWd). | Monthly customer charge $130.00, $0.05568/kWh, demand charge $22.25 per kWd. Example average monthly bill ~$29,067.10 (2026). Plus monthly PPA. | — |
Rate Recommendations by Use Case
Large commercial facility (GS2)
Attack the demand charge first.
At $22.25/kWd, demand is the dominant cost on GS2 while energy is only $0.05568/kWh, so peak shaving yields the most savings.
- Use Empower 15-minute data to find peak intervals
- Stagger startups and cap coincident demand
- Model the monthly PPA into bill forecasts
Extra large / industrial load
Optimize high-demand operations.
At ~750 kWd the demand component dominates a ~$29,067/month bill; small percentage demand reductions are material.
- Pursue load shifting and on-site storage where viable
- Continuously monitor Empower interval data
- Coordinate maintenance to avoid peak coincidence
Energy consultant / auditor
Gather data efficiently without an API.
Empower self-service CSV export is faster than a utility data request; use the manual 220 ILCS 5/16-122 process only when a utility-issued release is required.
- Have the client export up to 3 years of Empower interval data
- Prepare written authorization for any utility-issued data
- Budget for possible reasonable fees and 1-2 week turnaround
Small business (GS1)
Focus on energy efficiency.
GS1 has no demand charge, so the $0.11933/kWh energy rate and the monthly PPA are the main levers; efficiency and load reduction drive savings.
- Reduce kWh through efficient equipment and scheduling
- Use Empower to spot off-hours waste
- Compare against the GS1 average bill (~$264/mo) as a benchmark
Historical Rate Trends
Naperville set 2026 rates following a 2024 rate study by Utility Financial Solutions, which established rates for 2025-2027 after a prior 2021 study covering through 2024.
January 1, 2026
January 2026 increase; average residential customer (844 kWh) sees about a $6/month increase to an average bill of $121.87, still roughly 16% below surrounding communities.
~+5%Overall trend: Gradually increasing to fund system maintenance, equipment replacement, and supply-chain cost pressures.
Next expected change: Rates are set through 2027 per the 2024 study; a subsequent rate study would inform post-2027 rates. PPA varies monthly.
Cost Optimization Strategies
For Naperville GS2 (large commercial+) accounts, the $22.25/kWd demand charge is the largest controllable cost. Combined with a low energy rate and a monthly PPA, the best savings come from demand management and using Empower interval data to find peaks.
Demand (kWd) management
For: GS2 large/very large/extra large commercial
Limit coincident peak demand by staggering equipment and using controls; each kW shaved saves $22.25/month on GS2.
Empower interval analysis
For: All C&I customers
Export 15-minute interval data from Empower to CSV and analyze peaks, base load, and off-hours waste to target reductions.
PPA-aware scheduling
For: C&I with flexible load
Track the monthly Purchased Power Adjustment and, where flexible, shift discretionary load to lower-cost periods to manage total energy cost.
To implement these strategies, you need your 15-minute interval data. Learn how to download City of Naperville Electric Utility interval data →
Frequently Asked Questions
How can a C&I customer or consultant obtain Naperville interval data?▾
The customer can self-serve 15-minute interval data through the Empower portal and export it to CSV/Excel (up to 3 years, 24-hour delay), then share it with a consultant. For a utility-issued release to a third party, the customer must provide written authorization under 220 ILCS 5/16-122 and the utility processes the request manually (typically 1-2 weeks, possible reasonable fee). There is no Green Button or API path.
What are the commercial rate classes and demand charges?▾
Small Commercial (GS1) customers pay a $41.77 monthly customer charge and $0.11933/kWh with no demand charge. Large Commercial and larger accounts (GS2) pay a $130.00 monthly customer charge, $0.05568/kWh, and a $22.25 per-kW (kWd) demand charge, plus the monthly Purchased Power Adjustment. These are 2026 rates from the utility's published rate table.
Does Naperville support Green Button, EDI, or a public API?▾
No. Naperville does not offer Green Button (DMD or CMD), EDI transactions, or a public/developer API. As a municipal utility with a captive customer base, it focuses on first-party portals (eBill, Empower). Third-party access is manual and authorization-based.
How is the Purchased Power Adjustment (PPA) calculated?▾
The PPA is a monthly bill adjustment based on actual power costs using a six-month rolling average. The PPA baseline is reset at each rate study so it is ultimately revenue-neutral to the utility. C&I customers should include the current PPA when estimating bills.
Can a third party access multiple commercial sites at once?▾
There is no aggregator portal or bulk access. Each account's data must be requested individually through the manual authorized process, or the customer can export per-site data from Empower and share it. Bulk/automated access is not available.
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