Nestology installs a UPS (uninterruptible power supply) on every security hub and NVR. During a power outage, your cameras, locks, and sensors continue running for 30-90 minutes depending on system size. Z-Wave and Zigbee sensors run on coin-cell batteries that last 1-3 years regardless of power. Your smart locks have their own battery backup. If internet goes down too, local automations and recording continue - only cloud-dependent features (remote access, voice commands) pause until connectivity returns.