Backup power for a Southern California home

Start with the outage you are planning for

Most Southern California outages fall into two groups. Short ones come from a blown transformer, a car hitting a pole or a heat wave. They last hours. Long ones come from a utility turning off power on purpose when wind and dry brush make a fire likely. California utilities call this a Public Safety Power Shutoff, or PSPS. The utility must inspect every mile of line before it turns power back on, so these can run a day or more. Read PSPS power shutoffs explained to see how notice works and which areas are hit.

Write down two things before you shop. How many hours do you want to cover? Which loads must keep running? A fridge, a few lights, a phone charger and Wi-Fi need far less than a house with central air, a well pump or medical equipment.

The five backup setups

Setup	What it does	Typical SoCal range, October 2026
Interlock kit and inlet	Lets a portable generator feed the panel through a plug	$400 to $1,800
Manual transfer switch	A separate switch box for chosen circuits	$400 to $1,300
Automatic transfer switch	Starts a standby generator by itself	$600 to $2,500
Critical loads subpanel	Moves key circuits to one small panel for backup	Often $1,200 to $2,800
Home battery	Silent, automatic, runs for hours on stored power	Electrical side about $1,500 to $4,000; the battery is priced separately

The battery hardware varies with capacity, brand and installer, so get written quotes. The electrical side is a desk estimate of $1,500 to $4,000, not a published range. The interlock and switch ranges come from a published cost guide. Details are on the generator interlock cost page.

How the connection works

A generator should never feed the house through a wall outlet. Utilities warn that this sends power backward through the meter and onto the street lines, which can hurt crews who think the line is dead. The safe options all do one job: they disconnect the house from the utility before the generator connects.

• A generator interlock kit does it with a metal slide on the main panel.
• A transfer switch does it with a separate switch for the circuits you pick.
• A generator inlet box is the outdoor plug that the generator cord connects to. It works with either of the above.
• A critical loads subpanel keeps a small battery or generator from having to carry the whole house.
• Home battery installation covers storage that switches over without you.

Generator or battery

A portable generator is the lowest cost per watt and can run for days if you have fuel. It is loud, it needs fuel, and it must run outdoors, away from windows and doors, because of carbon monoxide. A battery has no exhaust, so it can sit in a garage or on an outside wall within the limits of the residential code. It will run out unless solar recharges it. Many homes in fire zones end up with a battery for the first day and a generator inlet as the backup to the backup. The full comparison is in generator vs battery backup.

Permits, inspection and who can do the work

Adding any of these changes your home wiring. Most cities require an electrical permit and an inspection. Batteries also face fire and location rules in the residential code. Work should be done by a California licensed electrician with a C-10 classification. Ask to see the license number and confirm it on the state license board lookup.

People who rely on power for health

If someone in your home uses medical equipment that needs electricity, ask your utility about Medical Baseline. The state program gives extra notice and extra electricity at the lowest rate, and the utility reaches out before a shutoff. It does not replace a backup plan. Make the plan with your doctor and your electrician before fire season, not after notice arrives.

Before the electrician visits

Know your panel brand and amp size, where the generator will sit, and the wattage of your must-run loads. Photos of the panel with the door open help. When you request quotes, ask for the permit and inspection to be listed as separate lines so you can compare bids.