ERCOT Solar + Battery Backup Guide: Grid Independence in Texas

A single 13.5 kWh battery (like the Tesla Powerwall 3) can power essential loads — refrigerator, lights, Wi-Fi, phone charging — for 12 to 24 hours depending on usage. However, if you run air conditioning, which draws 3,000 to 5,000 watts in a Texas summer, a single battery may only last 3 to 5 hours. For AC backup, you need at least 2 batteries (27 kWh). With solar panels recharging the battery during the day, you can extend backup duration indefinitely for essential loads.

Yes, but only if your solar system is paired with a battery and has islanding capability. During a grid outage, a standard grid-tied solar system without a battery shuts down for safety (anti-islanding protection). When you have a battery, the system creates a microgrid that isolates your home from the utility grid. Solar panels charge the battery during the day, and the battery powers your home at night. This cycle can continue indefinitely, giving you true grid independence during extended outages.

DRRS (Distributed Resource Registration System) is a new ERCOT program launching in 2026 that allows residential batteries to participate in grid services for the first time. When ERCOT faces a grid emergency (like extreme heat or cold), it can dispatch registered batteries to inject power back into the grid. Battery owners receive compensation for this service. Think of it as getting paid to share your battery during peak demand. Compensation rates are still being finalized, but the program is modeled after similar demand response programs in other states like ConnectedSolutions in New England.

No. The Section 25D residential energy tax credit expired on December 31, 2025. Homeowners who purchase a battery (or solar + battery system) with cash or a loan in 2026 receive zero federal tax credit. However, if you obtain your battery through a lease or power purchase agreement (PPA), the third-party system owner (financing company) may still claim the Section 48 or 48E commercial investment tax credit, which could lower your monthly payment. There is no state-level battery incentive in Texas currently.

A single battery installation in Texas typically costs $10,000 to $16,000 depending on the brand and installer. The Tesla Powerwall 3 averages about $12,500 installed. The Enphase IQ Battery 5P (2-unit system for 10 kWh) runs $10,000 to $12,000. The Franklin WholePower at 13.6 kWh costs $14,000 to $16,000. For whole-home backup with 2 or more batteries, expect $20,000 to $35,000+. Installation costs in Texas tend to be slightly lower than coastal states due to lower labor costs and fewer permitting barriers.

It depends on your priorities. A battery is silent, requires no fuel, recharges automatically from solar, produces no emissions, and can qualify for future DRRS grid service revenue. A generator is cheaper upfront ($3,000 to $8,000 for a whole-home unit), provides unlimited runtime as long as you have fuel, and can power larger loads including central AC. Many Texas homeowners are now choosing a hybrid approach: one battery for essential loads and automatic switchover, plus a portable generator for extended multi-day events when AC is critical.

Winter Storm Uri in February 2021 left 4.5 million Texas homes without power for up to 4 days in sub-freezing temperatures, resulting in over 200 deaths and billions of dollars in damage. The event shattered the assumption that the ERCOT grid is reliable. Texas battery installations grew by over 300% in the years following Uri. Homeowners realized that ERCOT operates as an isolated grid — it cannot import power from neighboring states during emergencies like grids in the Eastern or Western Interconnection can. A battery provides the only guaranteed residential backup beyond a generator.

Without DRRS grid services, a battery in Texas has an 8 to 12 year payback period. The primary financial value is backup power during outages, not energy arbitrage, because most Texas REP plans use flat rates rather than time-of-use pricing. With the new ERCOT DRRS program, payback could improve to 6 to 8 years once compensation rates are established. For CPS Energy customers in San Antonio, batteries improve payback by storing solar for evening use instead of exporting at the low 3-4 cent avoided cost rate. The intangible value of peace of mind, especially after Winter Storm Uri, is significant for many Texas homeowners.

Yes, in most cases. If you have a string inverter system, you will likely need a battery with an integrated inverter (like the Tesla Powerwall 3 or Franklin WholePower) or a separate hybrid inverter to manage both solar and battery. If you have Enphase microinverters, the Enphase IQ Battery 5P integrates seamlessly. Your installer will need to update your interconnection agreement with your TDU (Oncor, CenterPoint, etc.) and may need to pull a new electrical permit. Typical retrofit installation takes 1 to 2 days.

Texas summers routinely exceed 100 degrees Fahrenheit, which can degrade lithium-ion battery chemistry faster than moderate climates. All major battery manufacturers rate their products for high temperatures: Tesla Powerwall 3 operates up to 122 degrees F, Franklin WholePower up to 122 degrees F, and Enphase IQ Battery 5P up to 113 degrees F. To maximize lifespan, install batteries in shaded locations, inside a garage, or on the north side of the house. Avoid direct afternoon sun exposure. A well-sited battery in Texas should still meet its warranty terms (10 to 15 years) without issues.