Alert Definitions

New England has more than 350 generators and power plants supplying bulk power to New England’s power grid. ISO New England, Inc. is the non-profit organization that oversees all those plants as well as the transmission of all that power across the grid.

Power Normal

During normal operation, ISO New England maintains a reserve capacity of approximately 2000 megawatts. The extra power is there to cover unforeseen circumstances, such as one or more power plants being shutdown for unscheduled repairs. It might also be needed during extremely hot or cold days when power requirements rise beyond normal levels.

On occasion, ISO New England must dip into the power reserve in amounts sufficient enough that they ask consumers to conserve energy using a system modeled after advisories issued by the National Weather Service.

Power Watch

A Power Watch is a request to all customers to voluntarily reduce electricity usage and is issued when the region's electricity supplies are expected to be tight.

Power Warning

A Power Warning is a more urgent appeal. It’s issued when electricity supplies are--or are expected to be—tight enough that rolling blackouts are a possibility.

A follow-up notification is always issued to the public once a Power Watch or Power Warning has been lifted and regular electricity usage can resume.