PJM issued “Transmission Security – Emergency Use of Backup-Generator Warning” during this month’s record-setting heat wave, but ultimately did not call on large-load customers to operate their backup generators, the grid operator confirmed. For operators, the episode offers the first real-world test of a new reliability tool designed to tap into large-load backup generation during grid emergencies. In its July 9 Operating Committee presentation, PJM placed the backup-generator warnings among a series of measures deployed as temperatures climbed across the region. The operator said no backup generators were operated in response to the warnings and no large-load backup generation was dispatched under the emergency procedure. A New Reliability Tool Among ManyThe Operating Committee presentation shows that PJM relied on numerous reliability tools during the heat wave.