In short: Some of them do.

Several storage systems that have launched recently have an “AC outlet”, also known as “emergency outlet” or “anti-blackout”. This is a Schuko socket that delivers electricity when the network goes down. These systems can also be used in homes that are not grid connected.

During power outages, like the “apagón” in Spain, Portugal and parts of France in April 2025, these systems provide critical base power to their customers, literally “keeping the lights on”. With sufficient storage capacity, and daily recharge with your solar kit, you can easily get through power outages also for longer periods of time.