I was surprised to hear of the large power outage across the Southwest last night.
Power was out from Yuma, AZ to San Diego, CA and into parts of Mexico. Approximately 5 million people were in a blackout – which started right around 4pm, in the heat of the afternoon and the start of rush-hour traffic.
According to the news reports and statements from APS, the outage was triggered by a worker who was removing some monitoring equipment at a sub-station in Yuma – the equipment had apparently not been working correctly. It must have been behaving very badly for the utility to send out a worker to remove it during the peak time of a hot summer day. The worst case scenario expected by APS was for a blackout in Yuma, AZ. That the outage spread to San Diego and Mexico was unexpected, and will be the focus of their outage investigation.
Back in 2009, there were talks about upgrading the US Transmission grid. An example of one plan is found at NPR.org. In the picture from NPR, if you click the Proposed Lines “off”, you can see that the San Diego area has only one medium sized transmission line feeding it – coming directly from Yuma, AZ.
Most of the power is back on this morning, and airports are beginning to recover from the disruption. But, maybe it’s time to revisit the idea of upgrading the US transmission grid?