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Tariff data · 2026-08-27
← Tucson Electric Power Co · AZ

Residential Time-of-Use TRREST - Three Phase

When does peak hit on Tucson Electric Power Co’s Residential Time-of-Use TRREST - Three Phase? Peak hits 3pm–7pm every day, all year.

  • peak19.17¢
  • mid13.14¢
  • off-peak11.98¢
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Every hour of the year at this rate, drawn to scale — 24 hours across, 12 months deep, height is ¢/kWh. The tallest bar is 19.2¢ (May, 3pm), the shortest is 12.0¢ (May, midnight) — 1.6× apart.
Weekdays
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Weekends
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

What does Residential Time-of-Use TRREST - Three Phase cost a year?

HouseholdUsesA monthPer yearWorks out to
Apartment

One or two people, no central air, no electric heat

4,866 kWh$77$92919.1¢ / kWh
Family home

Three or four people with central air conditioning

9,453 kWh$129$1,54816.4¢ / kWh
Home with an EV

Same house, plus an electric car charging overnight

13,103 kWh$170$2,03815.6¢ / kWh

Estimates, not quotes. We run three made-up but realistic households through this tariff hour by hour for a full year — including the way air conditioning loads the afternoon and an EV loads the small hours. Your own bill depends on when you actually use electricity, which is exactly the thing a per-kWh number hides.

What you actually pay

PeriodRateApplies when
peak19.17¢ up to 500 kWh20.48¢ up to 1000 kWh21.21¢3pm–7pm, May–September
mid13.14¢ up to 500 kWh14.44¢ up to 1000 kWh15.17¢6am–10am, 5pm–9pm, October–April
mid12.28¢ up to 500 kWh13.58¢ up to 1000 kWh14.32¢9pm–6am, 10am–5pm, midnight–midnight, October–April
off-peak11.98¢ up to 500 kWh13.28¢ up to 1000 kWh14.01¢7pm–3pm, midnight–midnight, May–September

Plus a fixed charge of $25.44 per month.

Should you be on Residential Time-of-Use TRREST - Three Phase?

This is a time-of-use plan, which means the clock decides your bill as much as the meter does. At the worst hour you pay 19.2¢ a kWh; at the best hour, 12.0¢ — 1.6× apart for identical electricity.

That gap is worth real money only if you can move load into it. Every kilowatt-hour a day you shift from 3pm to midnight is about $26 a year. A dishwasher run is roughly 1.5 kWh; an EV commute charge is 8 to 12. If your day is fixed — you are home in the evening and the air conditioner runs when it runs — a plan like this costs you more, not less.

There is a usage cliff to watch. The first 500 kWh each month are billed at 12.0¢; past that line the rate steps up to 13.3¢ — 11% more for every unit after. The last kilowatt-hour of a heavy month is the expensive one, which is why cutting a little off a big month saves more than cutting the same amount off a small one.

Before a single kilowatt-hour moves, this plan charges $305 a year in fixed fees. On the apartment above that is 33% of the whole bill; on the house with a car charging in it, 15%. Fixed charges are invisible in a cents-per-kWh comparison and they punish small users hardest — if you use very little electricity, the headline rate is the least important number on this page.

Expect the bill to move with the calendar. The same family home costs about $178 in July and $100 in February — a $78 spread driven by heating and cooling far more than by anything you chose. Budget against the July figure, not the average, and a summer bill stops being a surprise.

How it compares to Tucson Electric Power’s other plans

Measured against the other residential plans this utility files, a family home lands 7th cheapest of 8. The cheapest option, Special Residential Electric Service Time-of-Use Program TRRSPT - Single Phase, would run about $123 a year less.

Against Residential Electric Service TRRES (Single Phase), which looks like the plan you land on by default, this one comes out $1 more per year (0%). We infer the default from the tariff structure rather than a flag in the data, so confirm it against your own bill before you switch.

Other Tucson Electric Power plans

Who can be on Tucson Electric Power’s Residential Time-of-Use TRREST - Three Phase?

Eligibility is not our judgement — it is written into the tariff Tucson Electric Power filed. This is what that document says:

Applicable for all single-phase residential electric service in individual private dwellings and individually metered apartments when all services is supplied at one point of delivery and energy is metered through one meter. The service shall be single phase, 60 Hertz.

Quoted from the filed tariff. Your utility decides eligibility, not us; check with them before you switch.

If this is new to you

Where this comes from

Effective
2025-09-30

the date this tariff took effect

Covers
delivery + supply

the ZIP-code service map lists this territory as bundled, so the utility sells delivery and supply together

Enrollment
open to new customers

Tariff document: https://docs.tep.com/wp-content/uploads/102-TRREST.pdf