Backup power is an emergency electrical supply that keeps critical systems running when the utility grid fails or power is interrupted. It usually includes batteries, uninterruptible power supplies (UPS), and generators that take over for servers, network gear, access control, and cooling long enough to ride out the outage or shut systems down safely.
In cyber security, backup power matters because an outage can be a security event as well as an availability problem. If monitoring, authentication, logging, or communications go dark, defenders lose visibility and response time. Attackers may also try to use power disruption as cover for intrusion, theft, or sabotage. Good defenses include redundant feeds, tested failover, fuel management, and regular drills so critical services stay stable during grid failures or deliberate utility interruption.