Anyone living in earthquake country like here in coastal California, would be wise to be prepared to exist off grid for at least a week. A big quake could greatly damage power infrastructure and in older cities like San Francisco that might consume any bandwidth for fixing power for weeks.
To do so requires alternative energy sources and gear to run modern lighting, flashlights, small telecom equipment, rechargeable battery chargers, cook food, and stay warm. Of course, at least a modest supply of food and water, and fire lighting devices also. Over decades, I've extensively backpacked in wilderness, and remotely dispersed camped in my vehicles, so have gear for and am familiar with using whatever.
Although one can buy a long list of portable energy products, for short term outages, one's lead acid battery within vehicles can also be used for larger capacity electrical power as long as one can transfer such power between vehicles outdoors then into a residence indoors with intermediate power storage devices. First that requires plugs from say one's automobile cigarette and auxiliary receptacle outlets, cabling to whatever storage devices, and connector adapters for any target devices. Generally keeping one's vehicle gasoline tanks reasonably full would of course be wise as one would expect a run on gas stations and food markets that could be disrupted from resupply for weeks. And then there is TP.
I own 5500 mahr, 10,000 mahr, and 40,000 mahr lithium power banks.
https://www.amazon.com/gp/product/B0C2423BW9/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&th=1
For portable lighting, I own a couple rechargeable LED work Lights. A smaller unit is 3,000 lumen while the below is a bright 100 watts 8,000 lumen multi-level light with a big 4,200 mahr battery.
https://www.amazon.com/gp/product/B07KYFSK94/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&th=1
For cooking that during emergencies would be done outside of residences, the classic camping standard used liquid white gas fuel in gallon cans but more recent products use canister propane gas fuel. For emergencies one needs both a stove, fuel, and actual experience using whatever.
A vehicles, AM and FM radios, can also be used for monitoring emergency information and news. Better is to also have a small portable battery operated AM/FM radio. A headlamp that frees up hands, will always be more functional for working in the dark. Also useful if all else fails are the hand crank type of emergency flashlights.
