GENERATOR AND BACKUP POWER · SAN ANTONIO
Generator and Backup Power in San Antonio, TX
Standby generators, interlocks, and transfer switches sized for what you actually need to run.
Keil Electric San Antonio installs generators and backup power across the San Antonio metro, from portable generator interlocks to whole-home standby systems on natural gas or propane. Master-licensed, TX #40645, (830) 214-8444.
San Antonio: Most days we're already in the area. Same-day appointments when capacity allows. After-hours emergencies dispatched when a licensed electrician is available, a real person at the local shop answers and tells you the ETA on the call.
Call nowFebruary 2021 changed how people in this part of Texas think about backup power, and the demand has not gone back down. The question we ask first is not what size generator you want, it is what you actually need running: for a house on a well outside Boerne or Bulverde, losing the pump means losing water, which changes the whole calculation.
Permits and inspections
Not every job requires a permit. When the local AHJ requires one, we pull it, schedule the inspection, and stay with the job until it passes. No paperwork on you.
What's covered
Written warranty: 5-year on outlets, fixtures, and EV chargers; 10-year on wire and breakers; lifetime on panelboxes and surge protection. Parts and labor. Transfers with the home.
What is different about generator and backup power in Texas.
Some of what we do for generator and backup power is shaped by the codes and conditions specific to Texas. Here is what tends to differ versus other states.
Code adoption in Texas
Texas adopts the National Electrical Code at the state level through the Texas Department of Licensing and Regulation, with most cities in the San Antonio metro adopting the most recent NEC cycle within a year or two of publication. Schertz, New Braunfels, Cibolo, and the other cities we cover each maintain their own permitting offices with slightly different inspection scheduling and form workflows. We track which cycle each AHJ in our coverage area is currently enforcing, so the scope we write for a job in Schertz is current to that city, not just current to "Texas." When a project crosses jurisdictions or sits in unincorporated county, we route the permit through the correct authority and tell you upfront which inspection cadence applies.
Hot-climate considerations
Summers across the San Antonio metro run long and hot, and that affects generator and backup power in ways that are easy to underestimate. Panels mounted on west-facing exterior walls run hotter all afternoon. Attic-mounted equipment derates per code because ambient attic temperatures regularly clear 130°F. AC compressors pull near-rated current for hours at a stretch through July and August, which puts more thermal cycling on terminations than the same equipment would see in a milder climate. We size conductors and breakers with that summer load profile in mind, not just the nameplate minimum. On older homes we look closely at terminations that may have loosened from years of heat cycling, those are a common cause of intermittent issues that get misdiagnosed elsewhere.
Severe weather and storm response
The metro sees thunderstorm hail, the occasional derecho, and the post-storm spike in generator and surge-protection demand that comes with each event. We keep enough surge-protection inventory at the shop to swap out a damaged whole-home unit same-day after a strike, and we know which generator and transfer-switch SKUs are realistic to source quickly when the supply chain tightens after a regional event. After the 2021 winter storm we also got a lot more careful about which loads customers actually need on backup, versus which loads end up on the generator only because nobody asked the question at install time.
Cities where we run generator and backup power.
We dispatch generator and backup power across the San Antonio area from our shop. Pick your city for the local page, or "See all cities" for the full coverage list.
Why hiring a licensed electrician matters.
For generator and backup power, here's the honest comparison. We'd tell you the same thing if we weren't trying to win the job.
A licensed electrician
Unlicensed for electrical
Doing it yourself
Spread the cost over time.
Pre-approval through Wisetack takes under 3 minutes. Soft credit check, no impact to your score.
- 0% APR for 3, 6, or 12 months (qualifying credit)
- 2–10 year low-interest plans for larger projects
- Soft credit check, takes less than 3 minutes
Financing through our partner Wisetack. Loan terms, APR, and approval subject to underwriting. Not all applicants qualify.
Common questions for Generator and Backup Power in San Antonio, TX
Whole home generator versus interlock kit - which makes sense?
A whole home standby generator is automatic, runs on natural gas or LP, and powers selected (or all) circuits during an outage. An interlock kit lets a portable generator safely back-feed the panel through a breaker. Whole home is more expensive and hands-off; interlock is cheaper and requires you to start the generator manually.
What size generator do I need?
Generator sizing starts with the loads you want to keep on (HVAC, refrigeration, well pump, medical equipment, lighting). We run the load calculation and recommend a size that matches without oversizing.
Where does a standby generator typically sit?
Outside the home on a concrete pad, away from windows and air intakes per manufacturer and code clearance rules. We confirm the pad location during the site visit.
Does a standby generator need a permit?
Yes - both the electrical interconnect and the gas connection (or fuel storage for LP) typically require permits and inspection. We handle the permit application as part of the project.
How long does a whole home generator install take?
A typical install runs 2-4 days on site once the equipment arrives, plus permit and inspection scheduling. Larger or more complex projects can extend; we confirm the timeline in the written scope.
Need generator and backup power in San Antonio?
Tell us about the project. A licensed San Antonio licensed electrician walks the job in person and writes a real scope, backed by our written warranty.