Whole House Generator Installation in Gadsden, AL

Gadsden Electrician Pros puts in home standby generators across Gadsden and the nearby towns of Attalla, Glencoe, Rainbow City and Southside. We size the unit to the circuits you want kept on, install the automatic transfer switch and wire it into your panel. For portable generators, we fit interlock kits and manual transfer switches so you can run part of the house safely through a storm. You get a free estimate before any work is booked. We're a licensed and insured electrician, and the site is left tidy once the generator is running.

Generator Work We Handle

• Standby generators: natural gas and propane units from popular brands such as Generac, installed outside
• Automatic transfer switches: the switch that moves the house onto the generator and back again
• Load management: modules that switch off heavy loads such as central air while the generator runs
• Portable generator hookups: panel interlock kits and manual transfer switches
• Replacement units: swapping an old standby generator and its transfer switch for a new one
• Panel checks: making sure the panel has room for the transfer equipment before the unit goes in

How a Standby Generator Works

A standby generator is fixed in place outside the house, much like a central air unit, and runs on natural gas or propane. An automatic transfer switch watches the utility supply. When it senses an outage, it disconnects the house from the utility lines and signals the generator to start. Generac's own figures put the time from the outage to the generator carrying the house at anywhere from 15 seconds to a little over three minutes, depending on the unit and conditions.

When Alabama Power restores the supply, the switch moves the house back onto the grid on its own, and the generator shuts down after a short cool-down. Left in auto mode, a Generac standby unit also runs a short scheduled "exercise" on its own, set weekly, every other week or monthly, with diagnostic checks while it runs. Depending on the model, the run lasts 5 to 20 minutes.

Sizing: Whole House or Essential Circuits

Generac advises sizing a generator around the appliances and systems you want to keep running, not square footage alone. There are two common approaches:

• Essential circuits: the fridge, some lights, a well pump if you have one and a few outlets. A smaller unit covers it.
• Whole house: heating or air conditioning, the kitchen and the other heavy loads as well.

The big loads decide the size. Generac lists central air, an electric range or oven, a well pump, an EV charger and an electric dryer, and notes that a 3-ton central air unit can need up to 15 to 18 kW just to start the compressor. As a rough guide from the same source, a 2,000 square foot house typically needs a 20 or 22 kW unit for whole-home coverage. A load management module can switch off non-essential, high-draw circuits automatically while the generator is running.

We work the size out from your panel and the loads you name, and check the panel has room for the transfer equipment. If it's old or full, our electrical panel upgrade page covers the options.

Natural Gas or Propane, and Where the Unit Sits

Natural gas runs from the meter, so there's no tank to refill. Propane needs a tank on site, and Generac sets a minimum of 250 gallons for its home standby units. The same engine usually makes a little less power on natural gas: Briggs & Stratton gives the example of a generator rated up to 20 kW on propane making up to 18 kW on natural gas. Either way, Generac says the fuel supply should be sized for the generator at full load by the gas provider or a licensed plumber, and the pipe size depends on the length of the run and the number of fittings. For propane, Alabama's LP-Gas Board rules make it unlawful to install or service LP-gas appliances without a current Board permit.

Placement is about exhaust as much as tidiness. Generac's guidance, based on NFPA 37, keeps the unit at least 5 feet from operable windows, doors, vents and other openings in the wall. Models tested by SwRI and carrying its logo can sit as close as 18 inches from a solid wall, with 3 feet clear at the front and ends and 5 feet above, though Generac notes some may still need more room to keep exhaust out. Local codes take precedence. On a tight lot, that can decide which side of the house the generator goes on.

Alabama Power's rules say a generator must be inspected by the local inspecting authority before it is connected to a home's wiring, and that a portable generator built for plugging in appliances must not be connected directly to home wiring. Inside city limits, the City of Gadsden Building Department issues electrical permits, and the city publishes a separate gas permit fee schedule. Outlying towns can set their own requirements, so a Southside or Glencoe address may differ. We'll go over permits when we come out to price the job.

Portable Generators: Interlock Kits and Transfer Switches

A portable generator can run part of the house through an outage, but only through the right connection. A panel interlock kit is a plate on the panel that allows only one of two breakers to be on at a time: the main breaker or the generator breaker. A manual transfer switch does the same job with a separate switch box. Either one means the house takes power from one source only, never both.

Never back-feed a panel through a dryer or wall outlet with a double-ended "suicide cord". Alabama Power warns that plugging a portable generator straight into home wiring can kill, and line workers repairing the lines may not know power is coming back down them. Keep a portable unit outdoors and 20 feet or more from the house (a garage doesn't count as outdoors), with battery-backed CO alarms on each floor.

Maintenance and Yearly Checks

Generac's yearly checklist covers looking for water getting in, checking the battery, testing the fuel line for leaks, looking for corrosion, and changing the oil and filter. Oil goes after the first 25 hours of running, then every 200 hours, or every 100 hours in extreme heat or cold, and at least every two years even if the unit has hardly run. Generator batteries last about three to five years on average. Spring and fall are Alabama's two severe weather seasons, so a check ahead of each one finds a tired battery while the grid is still up.

Typical Generator Installation Prices

Here are typical prices from published cost guides, as of October 2026. Few guides break out Alabama, so most are national figures. They are a rough guide, not our rates: the free estimate after we've seen your panel and where the unit would sit is the price that counts.

Storms and Outages in Etowah County

When a severe thunderstorm with 80 to 90 mph straight-line winds hit in August 2023, more than 10,800 customers across Etowah County lost power, including over 5,700 in Gadsden, and the city set up cold storage trucks for residents' food. The next day, Alabama Power still listed about 2,948 county customers without power. Before one winter storm, the National Weather Service put Etowah County among the counties at greatest risk of ice, warning that up to an inch could bring down tree limbs and knock out power. In January 2026, Alabama Power said it was bringing in more than 2,000 outside workers ahead of a winter storm.

For a lot of households, the clock starts with the fridge. FoodSafety.gov says a fridge keeps food cold for about 4 hours with the door shut, and a full freezer holds its temperature for about 48 hours if it stays closed. For a fault after the storm passes, see our emergency electrician page, and our other services are on the Gadsden Electrician Pros homepage.

Home Generator FAQs

Still have a question?

Still weighing up a generator? Call (256) 563-⁠5225 or send the quote form with what you'd like kept running, and we'll arrange a free estimate.