How Circuits Are Chosen For Rotating Blackouts
We received many comments today from customers interested in knowing how Austin Energy selects circuits as candidates for emergency rotating blackouts and inquiries as to why there appeared to be an uneven distribution of circuits involved in today's rolling outages. We appreciate your comments and concerns and would like to better explain this process as it applied to today's activity:
Austin Energy has 350 circuits that deliver power throughout our community. For the purposes of rotating blackouts, circuits that serve hospitals and emergency resources are excluded. In addition, circuits that serve large industrial customers and downtown Austin are excluded because the electrical loads are very large and therefore very difficult to bring back up. Also excluded are about 125 circuits with special equipment that provides the framework ensuring a stable system frequency of the Austin Energy electric system. Dip into that framework and you increase the risk of bringing the Austin Energy system down. This leaves about 50-75 circuits available for rotating blackouts. The load shedding requirement Austin Energy had to initially meet required rotating blackouts for 35-40 circuits. This necessitated repetition of this smaller number of available circuits to meet the load shedding requirements. As a result, some streets or neighborhoods experiencing outages were in some cases literally next door to others that did not.
In addition, some customers with outages much longer than the 30-40-minute rolling outage window in a number of cases had true outages that could only be addressed after the rotating blackout period ended this afternoon.
Thank you again for your inquiries and for following Austin Energy on this blog and on Twitter (http://www.twitter.com/austinenergy) for continuing news and updates.
