I blogged previously about tracking the progress of tornadoes across Alabama Power's territory by mapping non-respondng smart meters.
The University of Tennessee Power Information Technology Laboratory has used a network of small, low-cost devices that plug into wall outlets to show the electric system dynamics of the Western Interconnect during the San Diego blackout in September of this year. The devices record frequency, phase angle, and voltage every few seconds and transmit the data via the internet to the University of Tennessee and Virginia Tech. GPS-synchronization of the network made it possible to show geographically how the system disturbance propagated.
The red dots on the map are the locations of the monitors. Each line on the graph represents the frequency recorded over time by a monitor. Frequency is shown as the vertical scale on the graph on the left and the color-coded map legend on the right.
The system frequency dropped below 60 cycles per second (Hz) for 25 seconds, indicating that demand was exceeded supply. After this period of insufficient supply, the system automatically shed load in San Diego. The blackout suddenly reduced system demand and frequency increased rapidly above 60 Hz.