Willis and Montgomery TX Battery Backup: What Changes North of Conroe
If you own a home in Willis or Montgomery, the grid is only half of your backup question. The other half is the lake. Lake Conroe sits right there, and when it rises, where you mount a battery matters as much as how big it is. This guide covers the parts of Willis TX battery backup that are different from the rest of the county.
Key Takeaways
- Entergy Texas lists Montgomery and Willis in its Conroe Network, so the utility side matches Conroe. The lake side does not.
- Lake Conroe reached about 205 feet in May 2024 against a 201 foot normal pool, with dam releases near 69,545 cfs (Fox 26 Houston, 2024).
- Texas SB 1252 stops cities from regulating the installation of home batteries up to 100 kWh. Placement and flood risk are now your call.
What is actually different about Willis and Montgomery?
In July 2024, Entergy Texas grouped Montgomery, Panorama Village and Willis into one restoration area, the Conroe Network, with an estimated restoration of no later than July 14 (Entergy Texas storm update, July 10, 2024). So your utility is the same one covered in our Conroe battery backup guide. We won't repeat that material here.
What changes is geography. Many homes north of Conroe sit on or near the lake, on larger lots, with second-home use and long driveways. Those details drive three decisions: where the battery goes, how big it should be, and what happens when you are not home.
A small caution: some rural pockets of the county are served by an electric cooperative instead. Check the name on your bill before you plan anything. Our Magnolia and west Montgomery guide explains how to tell.
Why does Lake Conroe change where you put a battery?
Lake Conroe has a normal pool elevation of 201 feet above mean sea level, and its highest recorded level is 206.24 feet, set on August 28, 2017 (San Jacinto River Authority, 2026). That is a five foot spread between normal and record. On a shoreline lot, five feet is the difference between a dry garage wall and a wet one.
It helps to know what the lake is for. SJRA describes Lake Conroe as a water supply reservoir, built in 1968 for the City of Houston, and the authority bought Houston's share in 2009 to serve Montgomery County (San Jacinto River Authority, 2026). It was not built as a flood control lake. That is a fact worth sitting with if you live beside it. SJRA's Lake Conroe Division handles reservoir operations and the structural integrity of the dam (SJRA Lake Conroe Division, 2026).
Citation capsule: Lake Conroe is a water supply reservoir with a 201 foot normal pool and a 206.24 foot record high from August 2017, operated by the San Jacinto River Authority. It was not designed for flood control, so shoreline owners should plan equipment placement around high-water scenarios rather than assume the dam will hold levels steady (SJRA, 2026).
What happened in May 2024, and what does it mean for backup power?
Heavy rain in Walker County and northern Montgomery County, reported at up to 16 inches overnight, pushed Lake Conroe past 205 feet by mid-afternoon on the day of the event. Releases at the dam climbed from 13,400 cfs in the early morning to 69,545 cfs by 3 p.m. (Fox 26 Houston, 2024). County officials warned people along the San Jacinto River below the dam to prepare for significant flooding.
Notice what that event was. It was a rain and flood story, and the power question came second. A flooded street can mean a closed road, a de-energized neighborhood and a house you cannot reach, all at once.
So the useful lesson for Willis and Montgomery homeowners is about placement. A battery that is dry and running is worth nothing if the unit is mounted low on a wall that took on water. Ask your installer to mount the battery and controller above the highest water line you can reasonably document for your lot. Our Woodlands hurricane prep guide makes the same point for Lake Conroe's downstream side.
How do you size a battery for a lake house or second home?
Start with the loads you cannot lose: the refrigerator, internet, lights, a well pump or sump pump if you have one, and any medical device. Then decide how many hours you want to cover. The right size depends on your list, not on your square footage.
Eos systems use one controller rated for 11.5 kW continuous and 17.1 kW surge. Capacity scales by adding battery modules. The Plus plan has 2 modules, 17.52 kWh usable, and Eos rates it at up to 12 hours at minimal load. The Premium plan has 4 modules and 35.04 kWh usable (Eos plan specifications).
Here is the plain arithmetic. At a steady 5 kW, which is a hot evening with the air conditioner cycling, 17.52 kWh lasts roughly 3.5 hours. At 1.5 kW of essentials only, it stretches much further. Cutting load with a priority panel is how you turn a mid-size battery into a long runtime.
What if the house sits empty part of the week?
Second homes carry a different risk. If the power fails while nobody is there, a refrigerator full of food and a sump pump still need to run. A battery covers that gap automatically, with no one on site to start a generator.
Ask any installer how you would see system status remotely, and what happens to your loads if the battery runs low while you are away. Get the answer in writing. We would rather you ask than assume.
What did Hurricane Beryl show about this part of the county?
Beryl came ashore near Matagorda as a Category 1 hurricane on July 8, 2024 (NPR via KUNC, 2024). Entergy Texas reported 252,460 customers affected across its territory, and about 126,000 had been restored by 7:30 p.m. on the Wednesday after landfall (Entergy Texas storm update, July 10, 2024).
By Friday morning, July 12, roughly 182,800 of those customers had been restored, with the utility expecting more than 75% back by the end of the day (Entergy Texas storm update, July 12, 2024). That means a large group of households were still waiting on day four.
What is the takeaway for a Willis home? The Conroe Network was given a worst-case date of July 14, six days after landfall. If a backup plan only covers a few hours, it is built for the wrong outage. Whether you need two days or three depends on your loads, and the planner can walk you through it.
Do you need a city permit in Willis or Montgomery?
Not for the battery itself, in most cases. Texas SB 1252 took effect on September 1, 2025. It defines a residential energy backup system as one providing no more than 50 kW or storing no more than 100 kWh, and it bars municipalities from adopting or enforcing an NEC amendment or any ordinance that regulates the installation or inspection of those systems (Texas Department of Licensing and Regulation, 2025).
Every Eos residential plan is under 100 kWh. So a city in Montgomery County is not the gatekeeper for your battery install. A municipally owned utility can still regulate inside its own service area, though your power company here is Entergy or a cooperative, not a city.
Two things still apply. State law requires the electrical work to be done by licensed Texas electrical contractors under the NEC and Texas Occupations Code Chapter 1305 (TDLR, 2025). And utility interconnection is a separate process with your power company.
SB 1252 does not touch several other questions. HOA rules, deed restrictions and flood-zone requirements remain separate, so check each one before you commit to a location on your lot.
How should lakefront owners handle flood insurance and the battery?
Most standard homeowners policies do not cover flood damage, and a new flood policy typically takes 30 days to become active (FEMA, 2026). That 30 days is the reason to ask about it now, not when the lake is already rising.
Tell your insurance agent about the battery either way. Equipment that is installed and documented, with photos and a mounting height, is easier to discuss with an adjuster than a system nobody wrote down.
When you request quotes, ask each installer for a mounting height in writing and a plan for where the controller and smart panel go. If they cannot answer, move on.
How do you decide between Willis, Montgomery and nearby plans?
Use this short checklist before you call anyone:
- Read your electric bill and confirm the company name.
- Look up your lot's flood zone and note your lowest finished floor.
- List the loads you cannot lose, including any pumps.
- Decide how many days you want covered.
- Ask where the battery and controller will mount, and at what height.
- Ask whether the house will sit empty, and how you will monitor it.
If you are near The Woodlands boundary, our Woodlands location page applies. If you are closer to Conroe proper, use the Conroe location page.
Or call Eos at 833-989-3737 to talk through your setup with an installer.
What does Eos not know yet?
Plenty of local figures simply are not public, and we won't guess at them. Entergy does not publish a per-town outage history for Willis or Montgomery that we could cite. Neither does SJRA publish a rule for how high a given street will flood at a given lake level. If someone quotes you those numbers with confidence, ask for the source.
Frequently Asked Questions
Who provides electricity in Willis and Montgomery, Texas?
Entergy Texas lists Montgomery, Panorama Village and Willis in its Conroe Network (Entergy Texas, 2024). Some rural addresses may be on a cooperative, so confirm the name on your bill before requesting any quote.
Is Lake Conroe built for flood control?
No. SJRA describes it as a water supply reservoir built in 1968, with a normal pool of 201 feet and a record of 206.24 feet (SJRA, 2026). Shoreline owners should plan for high water instead of assuming the dam manages it.
Does my city issue a permit for a home battery?
Under SB 1252, a municipality cannot regulate the installation or inspection of a residential energy backup system of up to 100 kWh (TDLR, 2025). Licensed electrical contractors and utility interconnection still apply.
How big a battery does a Willis home need?
It depends on your loads and target hours. Eos lists the Plus plan at 17.52 kWh usable and the Premium at 35.04 kWh, both with 11.5 kW continuous output (Eos plans). The planner turns your load list into a recommendation.
Does homeowners insurance cover lake flooding?
Most standard homeowners policies do not cover flood damage, and a new flood policy typically takes 30 days to become active (FEMA, 2026). Ask your agent before storm season, not during it.