If you're considering solar in the Phoenix metro area, your utility provider — APS or SRP — has a major impact on your savings. The two utilities use completely different billing structures for solar customers, and the math looks very different depending on which one serves your home.
| APS | SRP | |
|---|---|---|
| Avg Residential Rate | $0.128/kWh | $0.119/kWh |
| Solar Export Rate | $0.076/kWh (RCP rider) | $0.028/kWh |
| Demand Charges | No | Yes — $9.16/kW on-peak |
| Basic Service Charge | $13.17/mo | $20.00/mo |
| Rate Plan for Solar | Saver Choice + RCP | E-27 (mandatory for solar) |
| Recent Rate Increase | ~8.5% (2025) | ~5.2% (2025) |
| Cities Served | Surprise, Buckeye, Goodyear | Gilbert, Queen Creek |
How APS Handles Solar Billing
APS uses a straightforward net billing system. When your panels produce more electricity than you're using, the excess flows to the grid and you receive credits at APS's export rate — currently $0.076/kWh through the Resource Comparison Proxy (RCP) rider.
This export rate is about 59% of what you pay to buy electricity from APS ($0.128/kWh). That gap means every kWh you use directly from your panels is worth more than every kWh you export. The implication: size your system to match your usage, not to overproduce.
APS Saver Choice + RCP Rider
- • Time-of-use pricing: electricity costs more 3-8 PM weekdays
- • Solar produces most during peak hours = maximum offset value
- • Export credits at $0.076/kWh regardless of time of day
- • No demand charges — billing is purely usage-based
How SRP Handles Solar Billing
SRP's solar billing is more complex. Solar customers are placed on the E-27 rate plan, which includes demand charges — a fee based on your highest single hour of electricity draw from the grid during on-peak hours each month. We break this down in detail in our SRP demand charges guide.
The demand charge is $9.16 per kW of your peak demand. If you pull 8 kW from the grid for one hour on a hot afternoon (say, your AC kicks on after sunset when solar production drops), you'll pay an extra $73.28 that month in demand charges alone.
SRP's export credit is also much lower: $0.028/kWh — less than a quarter of APS's rate. This makes self-consumption even more important for SRP customers.
SRP Demand Charges — Key Facts
- • Charged on your highest single on-peak hour each billing cycle
- • On-peak: 2-8 PM weekdays (summer), 5-9 AM & 5-9 PM (winter)
- • Solar helps during summer peak (sun is up) but less during winter evening peak
- • Battery storage can eliminate demand charges almost entirely
SRP Rate Plan Options
SRP requires solar customers to be on E-27, but has introduced newer plans:
- E-27: Standard solar customer plan with demand charges
- E-28: Newer option with different TOU windows — may benefit some solar customers
- E-16: Battery-paired plan with incentives for demand management
Which Utility Is Better for Solar?
APS is simpler and generally more favorable for solar — no demand charges, a higher export rate, and straightforward time-of-use billing. Your solar savings are more predictable and easier to calculate.
SRP is more complex but still makes solar worthwhile — especially if you add battery storage to manage demand charges. Without a battery, SRP solar savings are lower because demand charges persist even with a large solar system. With a battery, you can nearly eliminate demand charges and capture most of the savings.
APS Advantages
- • No demand charges
- • Higher export rate ($0.076/kWh)
- • Simpler billing — easier to predict savings
- • Solar alone delivers strong ROI
SRP Advantages
- • Lower base rate ($0.119 vs $0.128)
- • Battery + solar combo can nearly zero out bills
- • Newer rate plans (E-28, E-16) improving over time
- • Lower recent rate increases (5.2% vs 8.5%)
Bottom Line
Solar makes financial sense with both utilities. APS customers see faster payback with solar alone. SRP customers get the best results when pairing solar with battery storage. Either way, Arizona's 300+ days of sunshine means your panels will produce power — the question is just how your utility values that production.
Use our calculator to see exact savings — try the Gilbert solar calculator (SRP territory) or the Surprise solar calculator (APS territory) to compare.
Sources
- APS Residential Rate Schedules — Saver Choice, RCP Rider (aps.com)
- SRP Electric Rate Schedules — E-27, E-28, E-16 (srpnet.com)
- Arizona Corporation Commission — Solar Rate Decisions
- NREL PVWatts Calculator — Solar production estimates