APS Solar Buyback Rates, RCP and Grandfathering

Identify your APS export-credit tranche, understand the ten-year rate period, and separate solar buyback credits from the rate you pay for grid electricity.

Sources reviewed: 2026-10-06

Confirm APS service and the account's solar status

Start with the utility name on the bill. APS and SRP are different utilities even when two homes are in the same metropolitan area. Tucson Electric Power also has a Resource Comparison Proxy program, but its rider does not establish an APS customer's credit. This guide reviews APS residential RCP materials, not a statewide solar payment.

Ask whether the account is on an eligible RCP arrangement, a grandfathered legacy solar rate, or a different applicable schedule. An installer saying 'net metering' is not sufficient identification. The APS rooftop-solar guidance and the assigned agreement are the starting points.

Identify the enrollment tranche before quoting a rate

The reviewed APS RCP schedule lists dated enrollment tranches. Its 2025 tranche covers September 1, 2025 through August 31, 2026 at $0.06171 per exported kWh. Its 2026 tranche covers September 1, 2026 through August 31, 2027 at $0.05554 per exported kWh. These are dated tariff entries, not interchangeable retail prices or a guaranteed assignment for any application.

The table below reproduces selected entries from the current APS RCP schedule. Match the account's confirmed cohort and eligibility to the schedule; do not substitute the latest figure into every older customer's bill.

Application timing and completion conditions both matter

The rider describes initial credit treatment linked to the interconnection application and conditions for completing installation and obtaining local approval. Its timing language includes a 180-day completion condition and an extension to 270 days for the described third-party or APS delays that are not the customer's or installer's fault. Do not read an application date alone as an unconditional rate reservation.

Have APS confirm which clause applies to your application, the documented delay circumstances and the completion deadline. Keep the application receipt, local inspection approval and final interconnection records. Read the RCP timing provisions alongside the Plan of Administration.

The ten-year period is not a frozen whole electric bill

The reviewed schedule says the customer's initial RCP rate applies for ten years from interconnection. After the initial period, the purchase rate in effect at that time applies and may change from year to year. This concerns the export purchase rate, not a promise that import prices, monthly charges or total electricity spending will stay unchanged for a decade.

A proposal should identify the cohort, start of the rate period, assumed import plan and the treatment after the initial lock. Current rider conditions also address changes to the system and account. Use the RCP rate-period provisions, not a general statement that solar 'locks your bill'.

Separate inverter generation, self-use and exported energy

Electricity used directly in the home is not an export. A hypothetical system generating 900 kWh while 500 kWh is used on site exports the remaining 400 kWh, assuming no battery or other losses in this simplified example. The purchased-energy credit applies to the eligible meter-recorded exports, not all 900 kWh of inverter production.

For an account confirmed eligible for the reviewed 2026 tranche, 400 exported kWh multiplied by $0.05554 gives about $22.22 before actual utility rounding and billing treatment. This is an original illustrative export calculation, not a total bill or annual savings estimate. Imports and other charges still require the assigned residential rate. Source: RCP exported-energy credit.

Understand monthly credit carryover and December treatment

The reviewed rider states that credits exceeding the otherwise applicable monthly bill carry to the next bill or subsequent bills as necessary. After the December bill, a remaining export-credit balance exceeding $25 triggers an automatic check; otherwise the credit carries to the following year. This is a dollar-credit rule, not permission to treat APS exports as a retail-valued bank of kWh.

The $25 threshold and December treatment come from the current RCP schedule. Recheck the live sheet for the billing period and distinguish it from a legacy account's settlement rules before applying it to a statement.

Review grandfathering before switching or expanding

The current schedule says a customer switching from a grandfathered legacy solar rate loses that status and cannot subsequently switch back. It also contains rules for system capacity increases, replacement equipment, existing installations and eligibility for a new rate lock. These are reasons to obtain a written account-specific answer before agreeing to a retrofit.

Do not assume an additional panel, a battery, a home sale or a rate-plan change has the same consequence. Ask APS to identify the applicable clause and how the proposed change affects the existing tranche and rate period. The RCP legacy and system-change provisions are more reliable than a general marketing claim about grandfathering.

What a plan or battery comparison still needs

Import timing, the eligible residential plan, seasonal prices, applicable demand definitions and fixed charges determine what electricity bought from APS costs. A battery additionally needs usable capacity, power, efficiency, reserve settings, dispatch assumptions and installed cost. A low export credit alone does not establish a battery's payback.

Use the official APS comparison tools with appropriate account information. Our annual energy-flow calculator can explain self-use and exports, but it does not reproduce an APS bill or choose a cheapest plan. Compare a proposal with the quote analyzer and require its tariff assumptions in writing.