APS battery planning worksheet

APS Battery Scenario Calculator

Compare one year of entered charge/discharge value and optional APS Storage Rewards without product presets, automatic tax credits, or hidden lifetime assumptions.

Page reviewed July 27, 2026

Assumptions and exclusions are shown below the result.

Arizona Public Service: Residential Time-of-Use 4pm–7pm Weekdays (R-TOU-E)Arizona Public Service: Storage Rewards program termsInternal Revenue Service: Residential Clean Energy Credit guidance

First-year battery scenario

Enter values from the battery specification, quote, utility plan, and your intended dispatch schedule. Neutral capacity, cycle, cost, incentive, and program defaults avoid implying a particular product or outcome.

kWh
%
%
days
$/kWh
$/kWh
$
$

Capacity convention: the entered capacity times the usable portion is treated as deliverable battery output. Enter 100% if the specification already lists usable capacity. Round-trip efficiency grosses up the grid energy needed to restore that output after a full discharge; it does not discount usable output a second time.

Enter a verified or deliberately modeled seasonal average delivered kW. The sourced formula uses that average across all event-hours—not a payment per event. This worksheet does not infer eligibility or performance from battery size because APS events can last one to four hours and measured delivery controls compensation.

Rate fields start with the current APS TOU-E summer off-peak and peak base energy charges. Replace them if another season, plan, rider, tax, or fee is relevant. No federal, Arizona, APS purchase-rebate, degradation, warranty, or product-cost value is inserted automatically.

First-year result

This is arithmetic on your entries, not a dispatch simulation or lifetime forecast.

Deliverable output

0.0 kWh

0.0 kWh grid charging input at entered efficiency

Value per cycle

$0.00

$0.00 discharge value − $0.00 charge cost

First-year value

$0

$0 from entered Storage Rewards average

Net upfront cost

$0

$0 entered incentives

Simple payback

Not available because entered net cost or first-year value is zero or negative. The result excludes standby consumption, partial cycling, control failures, demand charges, degradation, maintenance, financing, taxes, and future program or rate changes.

How the cycle calculation works

Deliverable output energy equals entered capacity multiplied by the usable percentage. Enter 100% when the specification already states usable capacity. The model divides that deliverable output by round-trip efficiency to estimate the grid energy needed to restore a full discharge. For each full cycle, it subtracts that charging-input cost from the value of deliverable output during the discharge period, then multiplies by entered cycle days.

This deliberately avoids guessing how often a controller will cycle, whether every cycle will be full, or how a particular battery will degrade. Use a specification sheet for capacity and efficiency, your utility plan for rates, and your own operating plan for cycle days.

APS rates are starting inputs, not a bill forecast

The rate fields start with summer off-peak and peak base energy charges from the named APS TOU-E tariff. The tariff excludes some bill adjustors, taxes, fees, and riders. A battery can also affect demand or other charges on some plans. Replace the starting rates and cycle count when they do not represent your account or intended dispatch.

Storage Rewards uses average delivered power

The optional program amount is seasonal average delivered kW across all event-hours multiplied by the published $110 per kW factor. It is not a payment for each event. APS may call up to 60 events during May 1-October 31; eligibility, participation, opt-outs, availability, and actual performance can change the average. The result is not guaranteed income. The worksheet multiplies only the average you enter; it does not derive eligibility or performance from battery capacity. APS says events may last one to four hours, while compensation depends on measured seasonal-average delivery across event-hours.

Credits, product cost, and backup performance

The worksheet inserts no automatic federal, Arizona, or APS purchase incentive and no default product price. IRS guidance says the federal Residential Clean Energy Credit is unavailable for property placed in service after December 31, 2025. Enter an incentive only after verifying your own eligibility. This page does not determine tax treatment.

The program arithmetic is not an outage design. This worksheet does not check startup surge, transfer equipment, critical-load wiring, medical-device needs, reserve state of charge, or outage duration. Use the separate backup load-sizing worksheet for load arithmetic, then follow equipment instructions and qualified electrical guidance.