Arizona Public Service Company (APS) Rate Selection Guide
Arizona Public Service (APS) is the state's largest investor-owned electric utility, serving roughly 1.4 million customers across 11 Arizona counties under Arizona Corporation Commission regulation. For commercial and industrial accounts, APS provides self-service billing and daily usage data through its online portal and mobile app, with AMI smart meters deployed to about 1.1 million premises. APS has not implemented Green Button Connect or a standardized third-party data API, so C&I data sharing relies on portal downloads, Letters of Authorization, and direct data-access agreements.
Arizona Public Service Company (APS) Rate Schedule Comparison
| Schedule | Type | Rate | Best For |
|---|---|---|---|
| E-32 S (Small) | Commercial | $0.11980/kWh summer (first 200 kWh/kW); demand $12.393/kW; $1.286/day | Small businesses, 21-100 kW peak demand |
| E-32 M (Medium) | Commercial | $0.11530/kWh summer (first 200 kWh/kW); demand $14.690/kW | Mid-size commercial, 101-400 kW |
| E-32 L (Large) | Industrial | $0.05641/kWh summer / $0.03800 winter; demand $29.422/kW; $3.307/day | Large facilities, 401 kW+, flat-load operations |
| E-32 TOU L | Industrial | On-peak $0.07741/kWh summer; off-peak $0.06334; demand on-peak $18.941/kW | Large facilities that can shift load off the 3-8 pm peak |
| E-35 (Extra Large) | Industrial | Structure-only — see tariff library | Very large industrial loads, 3,000 kW+ |
Market Overview
APS operates as a regulated, vertically integrated investor-owned utility under the Arizona Corporation Commission. Commercial and industrial customers take bundled service (generation, transmission, and distribution) under ACC-approved tariff schedules; there is no competitive retail supplier choice. Rates were last established in ACC Decision No. 79293, effective March 8, 2024.
Need to pull your actual usage data to compare rates? See the Arizona Public Service Company (APS) Data Access Guide →
Current Rate Schedules
APS commercial and industrial customers are assigned to a General Service (E-32) tier based on their average summer monthly maximum demand: Extra Small (≤20 kW), Small (21-100 kW), Medium (101-400 kW), and Large (401 kW+), plus Extra Large (E-35, 3,000+ kW). Within each tier, customers choose a non-time-of-use plan or a time-of-use plan. Larger plans have a three-part structure: a daily basic service charge, a demand charge ($/kW of 15-minute maximum demand), and a seasonal energy charge ($/kWh, higher in the May-October summer season). The figures below are verified from APS tariff sheets effective March 8, 2024 (ACC Decision No. 79293).
Effective: March 8, 2024 · Full Tariff Book →
| Schedule | Type | Applicability | Structure | Rate |
|---|---|---|---|---|
| E-32 S — Small General Service (21-100 kW) | commercial | Non-residential customers with an average summer monthly maximum demand of 21-100 kW. | Three-part: daily basic service charge + demand charge ($/kW of 15-minute max demand) + seasonal energy charge ($/kWh, two-tier per kW of demand). | Energy: $0.11980/kWh summer / $0.10198/kWh winter (first 200 kWh per kW); $0.07507 summer / $0.05739 winter (additional kWh). Basic service: $1.286/day (self-contained meter).+ $12.393/kW first 100 kW, $7.063/kW additional (secondary voltage) |
| E-32 M — Medium General Service (101-400 kW) | commercial | Non-residential customers with an average summer monthly maximum demand greater than 100 kW and up to 400 kW. | Three-part: daily basic service charge + demand charge ($/kW of 15-minute max demand) + seasonal energy charge. | Energy first 200 kWh/kW: $0.11530/kWh summer / $0.09774/kWh winter; additional kWh $0.06662 summer / $0.05018 winter. Basic service $1.286/day (self-contained).+ $14.690/kW first 100 kW, $8.068/kW additional (secondary voltage) |
| E-32 L — Large General Service (401 kW+) | industrial | Non-residential customers with an average summer monthly maximum demand of 401 kW and greater that do not qualify for E-34 or E-35. | Three-part: daily basic service charge + demand charge ($/kW of 15-minute max demand) + seasonal energy charge. Aggregated accounts ≥5 MW eligible for a small generation-charge discount. | Energy: $0.05641/kWh summer / $0.03800/kWh winter. Basic service: $3.307/day (self-contained), up to $41.918/day at transmission voltage.+ $29.422/kW first 100 kW, $20.245/kW additional (secondary voltage) |
| E-32 TOU S — Small General Service Time-of-Use (21-100 kW) | commercial | Non-residential 21-100 kW customers choosing a time-of-use plan; on-peak 3:00-8:00 pm Mon-Fri. | Three-part with separate on-peak and off-peak demand charges and TOU energy charges (higher on-peak, summer May-Oct). | Energy on-peak $0.07883/kWh summer / $0.06177 winter; off-peak $0.05998 summer / $0.04559 winter. Basic service $1.286/day (self-contained).+ On-peak $21.620/kW first 100 kW, $10.918 additional; off-peak $8.636/kW first 100 kW, $2.970 additional (secondary) |
| E-32 TOU M — Medium General Service Time-of-Use (101-400 kW) | commercial | Non-residential 101-400 kW customers choosing a time-of-use plan; on-peak 3:00-8:00 pm Mon-Fri. | Three-part with separate on-peak/off-peak demand charges and seasonal TOU energy charges. | Energy on-peak $0.07973/kWh summer / $0.06444 winter; off-peak $0.06629 summer / $0.05099 winter.+ On-peak $19.850/kW first 100 kW, $12.689 additional; off-peak $7.476/kW first 100 kW, $3.681 additional (secondary) |
| E-32 TOU L — Large General Service Time-of-Use (401 kW+) | industrial | Non-residential 401 kW+ customers choosing a time-of-use plan that do not qualify for E-35; on-peak 3:00-8:00 pm Mon-Fri. | Three-part with separate on-peak/off-peak demand charges and seasonal TOU energy charges; the most common rate for large facilities able to shift load off-peak. | Energy on-peak $0.07741/kWh summer / $0.06140 winter; off-peak $0.06334 summer / $0.04728 winter. Basic service $3.307/day (self-contained).+ On-peak $18.941/kW first 100 kW, $12.654 additional; off-peak $7.025/kW first 100 kW, $3.695 additional (secondary) |
| E-35 / E-32 L SP — Extra Large & Storage Pilot | industrial | Extra Large general service for customers with average summer demand of 3,000 kW or more for 3 consecutive months (E-35); a Larger General Service Storage Pilot (E-32 L SP) is also offered. | Three-part demand/energy structure with specialized terms; see the APS tariff library for current E-35 and storage-pilot rate sheets. | Structure-only — see APS tariff library for current E-35 and storage-pilot figures.+ See E-35 / E-32 L SP tariff sheets |
Rate Recommendations by Use Case
Small business / retail or office (21-100 kW)
Small commercial accounts on E-32 S pay a modest daily charge plus a demand charge and a two-tier seasonal energy rate. If your load is steady through the day, the non-TOU E-32 S is simplest; if you can avoid the 3-8 pm peak, evaluate E-32 TOU S.
At 21-100 kW the demand charge ($12.393/kW first 100 kW) is meaningful but not dominant, so the choice between flat and TOU hinges on whether you can shift afternoon load.
- Track your 15-minute peak — a single spike sets the monthly demand charge
- Shift HVAC pre-cooling and equipment cycles out of the 3-8 pm window if on TOU
- Summer (May-Oct) rates are higher; tighten controls seasonally
Mid-size commercial / light industrial (101-400 kW)
E-32 M accounts face a higher demand charge ($14.690/kW first 100 kW). Demand management and load scheduling drive the bill; TOU can help facilities that can move production or cooling off-peak.
Demand charges scale with peak kW, so peak shaving and staggering equipment startups yield the biggest savings at this tier.
- Stagger large motor/compressor starts to limit coincident peaks
- Consider battery storage to shave the 15-minute demand peak
- Model TOU vs. non-TOU using interval data before switching
Large facility with steady, flat load (401 kW+)
Large flat-load operations (data centers, continuous manufacturing) often do best on E-32 L, where the energy rate is low ($0.05641/kWh summer) but the demand charge is steep ($29.422/kW first 100 kW). High, consistent load factor is rewarded.
With a high load factor and limited ability to shift load off-peak, the flat E-32 L avoids TOU on-peak energy premiums while the low energy rate keeps variable cost down.
- Maximize load factor — the demand charge is fixed regardless of when energy is used
- Pursue power-factor correction to avoid penalties
- If multiple sites total ≥5 MW, contract for the aggregated generation-charge discount
Large facility able to shift load off-peak (401 kW+)
Facilities that can curtail or shift load away from the 3-8 pm weekday peak should compare E-32 TOU L against E-32 L. TOU lowers off-peak energy and splits demand into on-peak and off-peak components.
TOU on-peak energy ($0.07741/kWh summer) is higher than flat E-32 L energy, but the lower off-peak energy and reduced off-peak demand charge ($7.025/kW vs. a single $29.422/kW block) reward genuine load shifting.
- Use battery storage or thermal storage to discharge during the 3-8 pm window
- Schedule batch processes and EV charging overnight
- Validate the switch with 12 months of interval data
Very large industrial load (3,000 kW+)
The largest loads should evaluate E-35 (Extra Large) and the E-32 L Storage Pilot. These specialized schedules carry custom terms — request current tariff sheets and a rate study from APS Solutions for Business.
At 3,000 kW+ the specialized Extra Large structure and storage-pilot terms can outperform standard E-32 L, but the figures must be pulled from the current tariff library.
- Contact APS Solutions for Business at (602) 371-6767 for a rate comparison
- Evaluate on-site storage to qualify for the storage pilot
- Model demand-response participation for additional value
Historical Rate Trends
APS's current commercial and industrial rate schedules were established in Arizona Corporation Commission Decision No. 79293, with tariff sheets effective March 8, 2024. This rate case reset the E-32 General Service tiers and demand/energy charges that apply to C&I customers today.
March 8, 2024
ACC Decision No. 79293 established the current E-32 General Service (S/M/L) and TOU rate schedules, with new daily basic service, demand, and seasonal energy charges effective March 8, 2024.
See ACC Decision No. 79293Overall trend: Following ACC Decision No. 79293 (2024), APS C&I demand and energy charges were reset upward as part of a broader base-rate increase. As a regulated utility, APS rates change through periodic ACC rate cases and ongoing adjustor mechanisms (fuel/power supply, system benefits) rather than market pricing.
Next expected change: Future changes will come through APS's next ACC general rate case and periodic adjustor true-ups; no specific next-change date is published here. Confirm current sheets in the APS tariff library.
Cost Optimization Strategies
For APS C&I customers, demand charges and seasonal/TOU energy pricing are the main cost levers. Because the demand charge is set by a single 15-minute peak, peak shaving, load scheduling, and storage deliver the highest-leverage savings — followed by selecting the right tier and TOU vs. non-TOU plan.
Peak demand management
For: All E-32 commercial and industrial tiers
Limit the highest 15-minute demand each month by staggering equipment startups, pre-cooling, and using automated load controls. On E-32 L the first-100-kW demand charge is $29.422/kW, so trimming peak kW directly cuts the bill.
Time-of-use load shifting
For: E-32 TOU S/M/L customers
On TOU plans, move load out of the 3:00-8:00 pm weekday on-peak window into lower off-peak periods. Batch processes, EV charging, and battery dispatch can be scheduled off-peak.
Battery / thermal storage for peak shaving
For: Large facilities with capital for storage
Discharge on-site storage during the monthly/on-peak demand window to cap the 15-minute peak and reduce demand charges; can also arbitrage TOU energy.
Rate tier and plan verification
For: All C&I customers
Confirm APS has assigned the correct tier (by average summer max demand) and run a TOU-vs-non-TOU comparison using 12 months of interval data before switching.
Multi-site generation-charge aggregation
For: Multi-site large commercial/industrial customers
Customers with multiple E-32 L / E-32 TOU L accounts totaling at least 5 MW can contract for a small per-kWh generation-charge discount.
To implement these strategies, you need your 15-minute interval data. Learn how to download Arizona Public Service Company (APS) interval data →
Frequently Asked Questions
How can my business access its APS usage and billing data?▾
Register a business account at aps.com, sign in, and use the multi-account dashboard and Solutions for Business usage tools. You can view and download up to 24 months of billing and daily usage data, plus on-peak/off-peak and demand breakdowns for applicable rate plans.
Does APS support Green Button or a data-sharing API for consultants?▾
No. APS has not implemented Green Button Download My Data or Connect My Data and does not publish an OAuth/REST API for customer data. Third-party access relies on customer-directed portal exports, a business Letter of Authorization, or a negotiated data-access agreement.
How does a consultant or aggregator get authorized to access our account?▾
For business accounts, complete and submit the APS Letter of Authorization to designate the third party as an authorized representative (typically renewed annually). For larger accounts, contact APS Solutions for Business at (602) 371-6767 to negotiate a formal data-access agreement.
Can we get 15-minute interval data from our AMI meter?▾
Granular 15/30-minute interval data is not exposed through the standard customer portal. Daily usage is available for download. Sub-daily interval access is generally limited to demand-response and DER programs; contact APS Solutions for Business to discuss interval data needs for specific analyses.
How far back does APS data go?▾
The portal provides up to 24 months (2 years) of billing and usage history for download.
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