With increasingly intense weather regularly knocking the power grid out, a lot of homeowners are looking into backup power systems. Traditional fossil-fuel–based backup systems — in the form of portable or permanent generators — remain a popular choice, but are vulnerable to the fuel shortages that often follow a natural disaster. That’s why residential solar power combined with battery storage (once an esoteric niche industry) is rapidly becoming a mainstream disaster-preparedness choice, according to more than a dozen installers, manufacturers, and industry experts we interviewed.But the solar battery market is rapidly evolving, and small, modular battery systems that can recharge from portable solar panels have become popular since we first wrote this guide in 2022. They cost less and require far simpler installation than rooftop systems, and have enough capacity to operate crucial household appliances like fridges and sump pumps, keep the lights on, and recharge communication devices — the basic necessities in an emergency. We cover them in this guide, too.The promise of using electric vehicles as home backup power is finally being realized, as well, with bidirectional EV chargers allowing some vehicles to use their huge batteries to run the house when the electricity is out. If you already own an EV, it’s an option worth exploring.In any guise, multi-kilowatt batteries deliver a reliable, low-maintenance, and resilient source of electricity in the event of a disaster. Here’s how you can set one up for your home.