APS vs SRP for Solar in Phoenix: Which Utility Is Better?

Your Utility Is Determined by Your Address, Not Your City

One of the most common misconceptions among Phoenix homeowners is that utility assignment follows city or ZIP code lines. It does not. APS and SRP serve overlapping ZIP codes across virtually every major city in the Valley, and boundaries often run along streets, rivers, or subdivision plat lines invisible from a map.

Some general patterns exist — but they come with important exceptions:

• Mesa: Entirely SRP service territory.
• Gilbert, Chandler, Queen Creek: Predominantly SRP.
• Buckeye, Surprise, Goodyear: Entirely or predominantly APS.
• Scottsdale: APS serves the northern portions; SRP serves the south. The boundary runs roughly through the middle of the city.
• Glendale: APS covers the northern part; SRP covers the southern part.
• Avondale: Split roughly along the Agua Fria River — APS west, SRP east.
• Tempe and Phoenix proper: Both utilities serve different neighborhoods within the same city.

The practical takeaway: do not assume your utility based on your city name. A neighbor two streets away may be on a different utility with very different solar economics.

How to Confirm Which Utility Serves Your Home

The most reliable method is one of the following, in order of simplicity:

1. Check your current electric bill. The utility name appears at the top of the first page. This is the definitive answer.
2. Use the SRP address lookup at srpnet.com. SRP's service area and territory page allows you to verify coverage.
3. Use APS's service area maps at aps.com/en/Residential/Service-Plans/Service-Area-Maps, where downloadable maps cover the Phoenix metro in detail.
4. Call your utility directly: APS at 602-371-7171; SRP at 602-236-8888.

If you're evaluating a home for purchase, confirm the utility before closing — switching is not an option. Your utility is assigned by service territory and cannot be changed by preference.

A Fundamental Difference: One Is Regulated, One Is Not

APS (Arizona Public Service) is an investor-owned utility and a subsidiary of Pinnacle West Capital Corporation. It is regulated by the Arizona Corporation Commission (ACC), a five-member elected body that oversees rates, solar policies, and interconnection rules through public regulatory proceedings. This means APS's export credit rates, solar tariff structures, and any proposed rate changes must go through a formal public process where homeowners, solar advocates, and other stakeholders can participate.

SRP (Salt River Project) is a not-for-profit public power utility and political subdivision of Arizona state. It is not regulated by the ACC. SRP's board of directors is elected by landowners within its district, and the utility sets its own rates, solar policies, and fee structures without ACC oversight or public rate cases. SRP's decisions on demand charges and solar compensation rates are made internally and are not subject to the same regulatory challenge process available for APS customers.

This distinction has practical consequences for solar homeowners. Changes to APS's solar policies — including export rate reductions — go through ACC proceedings with public comment opportunities. SRP's solar rate structures, including the demand charges that significantly affect solar economics, have been revised with limited external recourse for affected customers.

Export Credit Rates: What Each Utility Pays for Your Excess Solar

When your solar panels produce more electricity than your home is using at that moment, the surplus flows to the grid. Both utilities credit you for this exported energy — but the rates are very different, and neither is close to the retail rate you pay to buy power.

APS: Resource Comparison Proxy (RCP)

APS moved away from traditional net metering in January 2017 following Arizona Corporation Commission Decision No. 75859. New solar customers now receive an export credit under the Resource Comparison Proxy (RCP) rider rather than full retail rollover.

The RCP rate is reviewed annually by the ACC and has been reduced by up to 10% each September since 2017. The key benefit for homeowners: the rate in effect at the time you sign your interconnection agreement is locked in for 10 years from that date.

Always verify the current RCP rate against APS Rate Rider RCP (A.C.C. No. 6241) at aps.com before finalizing system economics.

At roughly $0.0617/kWh for the current tranche, the APS export credit represents approximately 40–50% of the retail rate APS customers pay for electricity. Every kilowatt-hour your system uses directly in your home — displacing retail-rate power — is worth considerably more than every kilowatt-hour you export.

APS also has a pending rate case before the ACC, filed in June 2025, requesting roughly a 14–16% overall residential rate increase. As of mid-2026, that case remains in its evidentiary phase; no new rates have been approved. If approved, rising retail rates would widen the gap between what you pay for power and what you earn for exports, further reinforcing the value of self-consumption.

SRP: Time-of-Use Export Plan Rate

SRP retired its net metering plans in November 2025. New solar customers are now placed on net billing plans. SRP's Time-of-Use Export Plan — the most straightforward of SRP's solar rate options — credits exported solar energy at a flat 3.45 cents per kilowatt-hour ($0.0345/kWh), regardless of what time of day the energy is exported. This rate is confirmed directly in SRP's published rate documentation at srpnet.com.

At 3.45¢/kWh, SRP's export credit is roughly half of APS's current rate, and represents only about 25–30% of what SRP customers typically pay to buy electricity from the grid. The practical implication is significant: kilowatt-hours exported to the grid under SRP are worth far less than kilowatt-hours consumed directly from your panels.

Side-by-Side Export Rate Comparison

Rates are subject to change; verify current figures directly with APS (aps.com) and SRP (srpnet.com) before making financial projections.

SRP's Demand Charges: The Factor That Changes the Entire Solar Equation

The export rate difference between APS and SRP is significant — but for many SRP customers going solar, the more consequential issue is demand charges.

What Is a Demand Charge?

A demand charge is a fee based not on how much total energy you use in a month, but on the single highest rate at which you drew power from the grid during a defined peak window. SRP's billing meters record electricity consumption in 30-minute intervals during on-peak hours. Your single worst 30-minute interval — even if it only happened once all month — sets your demand charge for that entire billing cycle.

Under SRP's Customer Generation Plan (a demand-based solar option), the demand charge is approximately $9.16 per kilowatt of that peak demand, applied in tiers that increase with usage. The math compounds quickly: if your AC, pool pump, and oven all run simultaneously for one 30-minute period on a July afternoon when your solar output has tapered off, you might pull 8–10 kW from the grid. That single interval could add $73–$176 to your monthly bill in demand charges alone — on top of your regular per-kWh energy charges.

Which SRP Solar Plans Have Demand Charges?

SRP offers two categories of solar rate plans, and the demand charge situation differs between them:

• Demand-based plans (Customer Generation Plan / Average Demand Plan): These include the ~$9.16/kW demand charge but offer lower per-kWh energy rates. Best suited to households that can actively manage and stagger peak loads.
• Export-based plans (Time-of-Use Export Plan, EV Export Plan): No demand charge. You pay only for energy consumed from the grid. The trade-off is you receive the 3.45¢/kWh export credit rather than offsetting at retail rates. This plan is often more predictable for homeowners who export regularly or prefer simpler billing.

SRP's on-peak hours for solar customers on the Customer Generation plan are typically 2–8 p.m. weekdays in summer and 5–10 p.m. weekdays in winter (excluding weekends and SRP-designated holidays). Confirm current hours at srpnet.com, as these vary by plan.

SRP charges a monthly service charge as well — typically around $30/month for a standard single-family home on solar plans. Confirm the current amount directly with SRP, as it varies by dwelling type.

APS: No Demand Charges on Standard Solar Plans

APS residential solar customers on standard time-of-use plans are billed purely on energy consumption (kilowatt-hours) — no monthly demand charge. APS's on-peak hours are typically 4–7 p.m. weekdays under its most common residential solar plan (R-3). Energy used outside those hours is billed at lower off-peak rates.

This simpler structure makes APS solar economics more predictable and generally more favorable for homeowners who cannot actively manage every load spike during peak hours.

How Each Utility Affects Solar + Battery Economics

APS + Battery Storage

On APS, a battery's primary value is time-shifting: storing midday solar production and using it during the 4–7 p.m. on-peak window when retail rates are highest (typically $0.25–$0.28/kWh in summer). This displaces high-cost grid purchases during the peak window, which is more valuable than exporting at ~$0.0617/kWh.

Batteries are beneficial on APS but not always essential for positive solar economics. A well-sized solar-only system with good self-consumption habits can still achieve meaningful bill reduction. The payback case strengthens considerably with a battery for households with evening-heavy electricity use.

SRP + Battery Storage

On SRP, a battery is far more central to solar economics — particularly for customers on demand-based plans. The core function of a battery in SRP territory is demand shaving: storing solar energy during the day and discharging it during the on-peak window to prevent any single high-demand interval from setting a large monthly demand charge.

With a properly sized battery system, SRP customers on demand-based plans can often keep their measured peak demand below 2–3 kW even during summer afternoons, reducing demand charges from a potential $80–$176/month to $18–$27/month — a monthly difference that substantially changes system payback math. Battery storage can essentially quadruple the effective value of excess solar production by converting low-value exports (3.45¢/kWh) into high-value demand reduction and self-consumption savings.

For SRP customers on the TOU Export plan (no demand charge), a battery's value is primarily time-shifting from midday solar production into the on-peak evening window — avoiding grid purchases at peak retail rates rather than exporting at 3.45¢/kWh.

Payback ranges are general estimates and vary significantly by system size, roof orientation, financing method, household usage patterns, and future rate changes. Get quotes sized to your actual usage before drawing conclusions.

So Which Utility Is "Better" for Solar?

On a like-for-like basis, APS is generally the more favorable environment for residential solar — particularly for homeowners considering solar without a battery. APS offers a higher export credit (roughly double SRP's TOU Export rate), no demand charges on standard solar plans, and a simpler billing structure where savings are more predictable.

That said, the full picture is more nuanced:

• SRP's overall retail rates are lower than APS's. SRP is a not-for-profit utility, and its base electricity rates have historically run meaningfully below APS's regulated rates. This means your starting bill — and the absolute dollar savings from solar — is lower on SRP even before considering export credits.
• SRP with solar + battery can be very effective. Homeowners who pair solar with a well-programmed battery on SRP's demand-based plans and actively manage their peak loads can achieve substantial bill reduction — sometimes near-zero monthly bills. The complexity is real, but so is the potential.
• The 10-year rate lock on APS is a significant advantage right now. Customers who interconnect under the current RCP tranche (~$0.0617/kWh) lock in that rate for a decade, providing cost certainty while retail rates may rise. APS has a pending rate increase request before the ACC that, if approved, would raise retail rates roughly 14–16% — widening the self-consumption advantage further.
• SRP has no public regulatory process for solar policy changes, meaning demand charges and export rates can shift without the external checks that constrain APS rate decisions.

The bottom line: if you are on APS, solar economics are straightforward and generally favorable. If you are on SRP, solar still makes financial sense — but you need to design the system around SRP's specific rate structure, and a battery changes the math significantly. In either case, work with an installer who knows your specific utility's interconnection process and rate plans inside out.

Homeowners in both APS and SRP territory can compare vetted local solar pros on VettedBest to get competing quotes from installers who are experienced with your utility's specific requirements.