Arizona APS and SRP Solar Interconnection and Approval Process

Why this matters

A residential solar install in Arizona is not finished when the panels are on the roof; it is finished when the utility grants permission to operate (PTO) and the meter is set to allow export. Arizona Public Service (APS) and Salt River Project (SRP) are the two dominant utilities, and they run distinct interconnection programs with different application steps, export-rate structures, and metering. Missing a step (submitting the wrong application, energizing before PTO, or skipping the city/county electrical permit and inspection) stalls the project, can void the interconnection, and leaves the customer with a system they legally cannot run for export. Knowing the sequence and the document checklist for each utility lets you set realistic timelines, avoid re-submittals, and keep the customer compliant. This is process knowledge, not legal advice; always confirm current utility tariff documents before each job.

Two utilities, two programs

APS is an investor-owned utility regulated by the Arizona Corporation Commission (ACC) and uses a net-billing / export-rate model rather than full retail net metering, with the export rate set periodically by the ACC. SRP is a public power utility governed by its own elected board and is not under ACC jurisdiction; SRP residential solar customers are placed on specific demand or time-of-use price plans and SRP metering differs from APS. Determine which territory the address sits in first, because the entire application path, forms, and economics diverge from there. Customers sometimes assume the rules they read online (often full net metering from other states) apply; in Arizona they generally do not.

The general sequence

Regardless of utility, the order is: site assessment and system design, electrical permit from the authority having jurisdiction (city or county building department), interconnection application to the utility, utility technical review and approval to install, installation and AHJ electrical inspection, utility meter exchange or reconfiguration, and finally permission to operate (PTO). Some steps overlap, but PTO is always last. Energizing for export before PTO is a violation of the interconnection agreement and can trigger disconnection.

APS application path

Submit the APS interconnection application with the system design (single-line diagram, equipment cut sheets for the modules and inverter showing UL 1741 SB listing, and site plan). APS reviews for system size against the service, anti-islanding compliance, and any required external disconnect. After APS approval to install and the local AHJ permit, complete the installation, pass the AHJ electrical inspection, and provide the signed inspection to APS. APS then exchanges or reconfigures the meter for the net-billing/export configuration and issues PTO. The customer is enrolled on the applicable APS rate with the current ACC-set export rate. Keep copies of the inverter listing, the single-line, and the inspection sign-off for the file.

SRP application path

Submit the SRP interconnection/generation application with the design package. SRP reviews and, importantly, the customer must move to an SRP price plan that accommodates customer generation, which typically involves a demand component; the installer should make sure the customer understands the plan change before commissioning. After SRP approval, the AHJ permit, installation, and the AHJ electrical inspection, SRP performs its meter work and issues approval to operate. SRP's metering and billing structure is its own; do not apply APS or generic net-metering assumptions to an SRP customer.

Documents and equipment to have ready

For either utility have on hand: a single-line electrical diagram, the AHJ-stamped electrical permit, manufacturer cut sheets proving the inverter is UL 1741 SB listed and the modules are listed, the racking and rapid-shutdown (NEC 690.12) details, and the array boundary labeling. Most AHJs require permanent placards per NEC 690.13, 690.56, and 705.12 marking the disconnect, the rapid-shutdown switch, and the point of interconnection. Have the customer's utility account number for the application. After inspection, retain the signed inspection card to submit for PTO.

Common stalls and how to avoid them

The most frequent re-submittals come from an incomplete single-line, an inverter cut sheet that does not clearly show UL 1741 SB listing, missing rapid-shutdown documentation, and energizing before PTO. Schedule the AHJ inspection only when the placards and disconnects are installed, because a failed electrical inspection forces a re-inspection and delays the utility meter step. Set customer expectations that PTO timing is utility-controlled and the system must stay off for export until the PTO letter arrives.

References

• Arizona Corporation Commission rules governing APS net-billing and export-rate decisions (current ACC decision applicable to the install date)
• APS Interconnection Requirements and Renewable Energy / DG application documents (current version)
• SRP Customer Generation interconnection requirements and applicable SRP price plan (current version)
• NEC 2023 Articles 690 and 705 (PV systems and interconnected power sources), 690.12 rapid shutdown, 690.13/690.56/705.12 marking and disconnects