Utah Power Outage Planning: Powerwall & RMP Guide

Updated: September 10, 2026. Editorial update by Ask Solar Mike.

Short answer from Ask Solar Mike, a Utah Tesla solar and Powerwall 3 specialist : backup planning for a Rocky Mountain Power outage starts with your actual energy use, simultaneous appliance demand and desired outage duration—not your panel amperage alone — one Tesla Powerwall 3 stores 13.5 kWh of usable energy and delivers 11.5 kW continuous power, 48 A maximum continuous current and a 185 LRA motor-start rating, per Tesla's public datasheet . Everything else on this page — the readiness checklist, the sizing logic, the rebate rules — flows from that one design decision . Here is the whole plan.

Manufacturer product image supplied by Tesla; not a photograph of an Ask Solar Mike installation.

Why do Utah homes lose power in the first place?

Utah outages tend to arrive with weather: canyon wind events that take down lines, heavy wet snow in shoulder season, and summer heat waves that push the grid to its peak. Add the ordinary causes — equipment failures, vehicle strikes, planned maintenance — and most homeowners along the Wasatch Front can count on losing power at least occasionally, usually at the least convenient hour. The difference between a bad evening and a non-event is whether you prepared while the lights were still on.

What should be in your outage readiness checklist?

Most of this list costs little and takes one afternoon:

• Save your utility's official outage-reporting line and app from its own website.
• Keep flashlights and charged power banks where you can find them in the dark — not in the junk drawer under the batteries you meant to replace.
• If you are on a well pump, store drinking water; the pump is a motor load, and it stops the moment the grid does unless a battery carries it .
• Learn your garage door's manual release — it is the red cord — and test it once.
• If anyone in the home relies on powered medical equipment, write the backup plan down and tell your utility; most utilities keep a medical-needs registry.
• During an outage, keep the fridge and freezer closed; a full freezer holds temperature far longer than an opened one.

That checklist keeps you comfortable for an evening. For anything longer — or for a home where the furnace blower, well pump or medical equipment cannot wait — the conversation becomes backup power.

What does whole-home backup look like with Powerwall 3?

Whole-home backup means the battery islands the entire electrical panel the instant the grid drops, through a Gateway 3, Backup Switch or Backup Gateway 2 at the service entrance, so the house simply keeps running . The numbers that make it work come straight from Tesla's public datasheet: 13.5 kWh usable energy per unit, 11.5 kW continuous output, 48 A maximum continuous current, and a 185 LRA load-start rating for motor loads like air-conditioner compressors and well pumps . Powerwall 3 also carries an integrated solar inverter accepting up to 20 kW DC across 6 MPPTs, and the datasheet supports up to four units for larger homes . Every system design is produced and reviewed by a licensed engineering firm . The full sizing logic for 100 A, 200 A and 400 A homes is in our whole-home backup guide.

How long will a Powerwall 3 carry your home?

Honest answer: it depends on what you run, which is why we size from your panel and your loads rather than quoting a runtime promise — a site-specific quote and load review are required . The physics are simple: each unit stores 13.5 kWh of usable energy, so a home drawing a steady 1 kW draws the battery down far more slowly than one running central air . Pair the battery with solar and a daytime outage changes character entirely: the integrated inverter keeps recharging the battery from the array while the grid is down, per the datasheet's up-to-20 kW solar input .

What does backup cost, and what does the Wattsmart rebate change?

From Ask Solar Mike, gross first: a Tesla Powerwall 3 is $16,000 installed → $11,200 after the 30% pre-paid PPA instant rebate → $9,200 after the $2,000 Wattsmart rebate — and that last step applies to Rocky Mountain Power customers only . If your home is on a municipal utility, the Wattsmart rebate does not apply and your after-incentive number is $11,200, not $9,200 . Full market context, with every number sourced and dated, is in our 2026 Utah cost guide . Comparing battery brands first? Start with the Powerwall 3 vs Enphase vs EG4 comparison .

Are you actually a Rocky Mountain Power customer?

This is the question most Utah battery quotes skip, and it moves the price by $2,000 . Utility service in south Utah County varies by address — Payson, Spanish Fork and Salem run their own city power in parts of town, SESD serves others, and some pockets are Rocky Mountain Power . The same street-by-street caution applies around Mapleton, Benjamin and the west-mountain areas, so we never assume: we confirm your serving utility as step one of every quote . Two cases are settled: Lehi and Provo run municipal utilities, so the Wattsmart rebate does not apply at those addresses . The fastest check is your own power bill — the utility name on it is the only one that counts .

Who is behind this page?

Ask Solar Mike is a licensed Utah contractor (DOPL #14015846-5501) and a Tesla Certified Installer — verify the current status in Tesla's public installer directory . The team behind Ask Solar Mike brings 2,000+ Tesla solar and battery installs of combined experience . Ask Solar Mike has a 4.9-star Google rating from 46 reviews .

Quick answers for the next outage

Will my solar panels work during an outage without a battery?

No — a standard grid-tied solar system shuts down when the grid goes down, a safety requirement that protects utility line workers. Adding a battery with an islanding gateway is what lets the array keep producing during an outage .

Will one Powerwall 3 start my air conditioner?

Tesla rates Powerwall 3's load-start capability at 185 LRA on the public datasheet; whether that covers your compressor depends on its nameplate, so a site-specific quote and load review are required .

Do I qualify for the $2,000 Wattsmart rebate?

The Wattsmart battery rebate is for Rocky Mountain Power customers only — municipal-utility homes, including Lehi and Provo, do not qualify . In south Utah County, utility service varies by address, so confirm your serving utility from your bill as step one .

How many Powerwall 3 units does a larger home need?

Tesla's datasheet supports up to four Powerwall 3 units, and the answer for your home comes from continuous load and motor starts, not square footage — a site-specific quote and load review are required . Our 100 A / 200 A / 400 A sizing guide walks through the logic .

Sources

• Tesla Powerwall 3 Datasheet, 2025 edition (13.5 kWh usable; 11.5 kW continuous; 48 A max continuous current; 185 LRA; up to 20 kW solar input, 6 MPPTs; up to 4 units; read 2026-08-30): energylibrary.tesla.com — Powerwall 3 Datasheet
• Rocky Mountain Power Wattsmart Battery program terms, effective June 15, 2026 ($2,000 enrollment incentive for a single battery 10 kW or larger; RMP customers only; read 2026-08-30): rockymountainpower.net — Wattsmart Battery