Texas + your home
Will my solar work in the next Winter Storm Uri?
February 2021's Winter Storm Uri left 4.5 million Texas households without power for days. Solar panels alone wouldn't have kept those lights on — grid-tied systems shut down automatically during outages to protect utility line workers from energized backfeed. That's federal code, not an installer choice.
What does keep your lights on is a battery — Tesla Powerwall 3 or Enphase IQ Battery 5P — that islands your home from the grid the moment it goes down. Solar charges the battery during the day, the battery powers your home at night and during the outage, and the grid is irrelevant until it comes back.
What happens to a grid-tied system during a Texas outage
- Utility loses power. Your meter reads zero.
- Your inverter detects the absence of grid voltage and shuts down within milliseconds (anti-islanding code: UL 1741, IEEE 1547).
- Your panels stop producing. Your home is dark, even if the sun is shining.
- When the grid comes back, the inverter waits 5 minutes to verify stability, then re-energizes.
What happens with a battery + transfer switch
- Utility loses power. Your meter reads zero.
- The battery's transfer switch (an automatic relay) disconnects your home from the grid in milliseconds.
- The battery starts powering your designated backup loads — typically lights, fridge, internet, fans, garage door, plus optionally HVAC if you sized for it.
- Solar continues producing through the day and recharges the battery.
- When the grid comes back, the transfer switch reconnects you, and the battery returns to its normal time-of-use cycle.
How long does a battery actually run a Texas home?
| Backup goal | Battery configuration | Approximate runtime in February conditions |
|---|---|---|
| Essentials only (lights, fridge, internet, fans) | 1× Powerwall 3 (13.5 kWh) | 12–24 hours |
| Essentials + microwave + small space heater | 2× Powerwall 3 (27 kWh) | 1–2 days |
| Whole home incl. central heat / cooling | 3–4× Powerwall 3 | 2–4 days, indefinite if sun returns |
| Modular Enphase build (5 kWh per IQ 5P) | 3–4× Enphase IQ 5P | Comparable per total kWh |
What Uri-grade events look like in 2026
Texas grid reliability has improved since 2021 (winterization mandates, expanded ERCOT reserves) but the underlying problem — extreme weather hitting an isolated grid — hasn't been solved. ERCOT issued conservation alerts in 2022, 2023, and 2024 summers. Hurricanes Beryl (2024) and Harvey (2017) caused multi-day Houston outages. The frequency has gone up, not down.
The pragmatic homeowner take: a single Powerwall is the floor for keeping a Texas family safe through extended outages. Two batteries gets you whole-home backup including HVAC. The math has gotten easier as battery prices keep dropping.
Common questions
Frequently asked
- Will solar panels alone keep my power on during an outage?
- No. Grid-tied systems shut down within milliseconds of grid loss to protect line workers (UL 1741 anti-islanding). You need a battery with a transfer switch to keep your home powered.
- What's the minimum battery size for a Texas home?
- One Tesla Powerwall 3 (13.5 kWh) or three Enphase IQ Battery 5P modules (15 kWh) covers essentials — lights, fridge, internet, garage door, fans — for 12-24 hours. Whole-home backup including AC/heat needs 2-4 batteries depending on home size.
- How does a battery handle multiple cloudy days during a winter storm?
- The battery discharges normally; solar production drops to 20-40% on cloudy winter days but doesn't stop. Smart-load management (turning off the dryer, prioritizing fridge/heat) extends runtime indefinitely if there's any daytime sun. We run that math during your design.