As California increasingly looks to neighboring states in the Southwest for new energy supplies, Arizona?s recent experience shows that any codependency can have its failing moments. Despite the return to service July 19 of Palo Verde unit 2?some 1,300 MW of capacity?after a weeklong outage, 50,000 Phoenix residents were left in the dark the next day because of a substation fire. A major substation fire July 4 did not result in blackouts but left Phoenix and the surrounding area on alert. Arizona Public Service asked customers to increase conservation by setting thermostats no lower than 82 degrees. Last month, blackouts plagued the state and reduced exports to California. According to reports, bird droppings on a high-voltage wire may have started the problem, tripping off all Palo Verde units as a relay station failed to isolate the damage.