How long will a home backup battery really keep your house running during a Texas power outage? Stop guessing. Simulate it.
This free outage simulator uses your real Smart Meter Texas usage data (or a typical home profile) to show how long a home battery like Base Power or Tesla Powerwall would actually last in your home, based on how you really consume electricity and on the hour, day, and month the outage occurs. It is built to set realistic expectations about backup duration, whether you already own a battery or are still deciding what backup power to buy.
We simulate the outage against your actual Smart Meter Texas consumption history, not against marketing averages or brochure numbers.
Backup time is not one fixed number. It changes with the hour, the day of the week, and the month the outage starts, and the simulation accounts for all of it.
Know what to really expect, before the lights go out.
First, tell us how you want to provide your home's electricity usage. Real Smart Meter Texas data gives the most accurate simulation; the home-size profiles are a good estimate if you don't have your CSV handy.
Privacy note: Your Smart Meter Texas CSV may contain detailed electricity usage information. We use this file only to run your battery simulation. We do not sell your usage data, use it for advertising, or share your uploaded CSV with anyone.
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Preparing your simulation...
Step-by-step Guide
To compare Free Nights electricity plans, you first need your Smart Meter Texas usage file. This file shows your electricity usage in 15-minute intervals, which helps estimate how much energy you use during the free-night window.
Go directly to SmartMeterTexas.com and log in with your username and password.
If you do not have an account yet, you will need to create one first. Most Texas homes already have a smart meter, so most users should be able to access this data.
This generates a CSV file. If you have a full year of data, the file may be around 3 MB. If you recently moved into your home or apartment, your file may be smaller because there is less usage history available.
About this tool
The Home Battery Calculator is a free tool built by Clear Energy Facts to help Texans understand what a home backup battery can really do for them during a grid outage.
Marketing pages usually quote a single "hours of backup" number. In reality, backup time depends on your home's actual consumption pattern, the season, the hour the outage starts, and how much you cut back once the power is out. This tool lets you test all of that with real interval data.
The simulation uses 15-minute interval usage data — either your own Smart Meter Texas export or a typical profile for your home size. Only consumption intervals are used; surplus solar generation rows are excluded, and duplicate readings for the same interval are summed.
Starting at the outage date and hour you select, the simulator subtracts each 15-minute interval's usage (scaled by your chosen consumption level) from the battery's stored energy until it reaches zero. The year in your data is ignored: what matters is the seasonal and daily usage pattern.
Battery capacities are the manufacturers' published usable energy figures. We assume no recharging during the outage — no solar and no grid — which makes this a conservative, worst-case style estimate for solar-paired systems.
Your uploaded Smart Meter Texas file is used only to run this simulation.
Results are estimates for planning purposes, not a guarantee of backup performance. Actual backup time depends on weather, battery age and health, inverter power limits, and your real behavior during an outage.
Always confirm system specifications and backup expectations with your battery provider before making purchase decisions.
