Solar batteries & home backup in Texas
After Winter Storm Uri, backup power became a top reason Texans add storage. But a battery does more than ride out an outage — and whether it pays off depends on your goals. Here’s what a home battery actually does, how to size one, and what they cost now.
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The four jobs a home battery does
1. Backup during outages
The headline use in Texas. When the grid goes down, a battery (with the right transfer setup) keeps chosen circuits — or your whole home — running, and your solar keeps recharging it by day. How long it lasts depends on capacity vs. the loads you back up.
2. Use your daytime solar at night
Store the solar you make midday and use it after sunset, instead of exporting it. This matters more in Texas because export buyback is often below the retail rate — keeping your own kWh can beat selling it cheap. See net metering in Texas.
3. Sell into peaks / grid-event programs
On a real-time or grid-event plan, a battery can discharge to the grid when ERCOT prices spike on hot afternoons — turning storage into income. Programs like Tesla Electric pay battery owners during grid stress. See the buyback plan types.
4. Time-of-use shifting
On a time-of-use plan, charge when power is cheap (or free from your panels) and avoid pulling from the grid during expensive peak hours.
How to size a battery
Power (kW) vs. capacity (kWh)
Two different numbers: power (kW) is how much it can run at once (can it start your AC?), and capacity (kWh) is how long it lasts. For backup, decide whether you want whole-home or just essential circuits (fridge, a few outlets, internet), then size for the hours you want to cover.
With most modern home batteries, you scale capacity by adding complete units in parallel — each unit is already at system voltage, so two units ≈ double the kWh. (True series stacking is the exception, for high-voltage strings.) The simulator builds a bank the same way.
A battery needs a hybrid (battery-capable) inverter, and systems are either AC-coupled (battery has its own inverter, easy to add to existing solar) or DC-coupled (shares the solar inverter, slightly more efficient). Either works; it’s mostly about whether you’re adding to an existing array or building new.
What they cost in 2026
Heads up: the federal tax credit that covered home batteries (Section 25D, which included storage of 3 kWh+) ended December 31, 2025 — so a battery bought in 2026 with cash or a loan no longer gets that 30% credit. See Texas incentives.
Without that credit, the payback case leans on the value you put on outage protection, the gap between your buyback and retail rates, and any grid-event income. For pure bill savings a battery rarely pays for itself on its own; for resilience plus the right plan, it can make sense.
Want to see how a battery changes your numbers — backup hours, self-consumption, and savings? Run a free estimate and add storage to the system. See how we model it on our methodology page.