PPL Electric Utilities is urging customers to use only essential power, and warned that temporary local power interruptions may be necessary to prevent widespread power disruptions in the mid-Atlantic region.

Unseasonably warm weather this week has caused unusually high demand for electricity that is exceeding the available electric supply.

Traditionally, utilities plan scheduled maintenance outages for many of their power plants in the early spring to avoid winter and summer peak demand periods. Bill Whitehead, PPL manager of transmission and delivery operations, noted that this may have contributed to the current situation throughout the region.

"This is a very serious situation," said Whitehead. "We use rotating interruptions as a last resort to preserve the electric transmission system. We urge customers to conserve electricity and use only the electricity they need to protect their health and safety."

During rotating interruptions, power is shut off to selected areas for about 30 minutes at a time. As power is restored in one area, it's shut off to another. Critical care customers, such as hospitals, are exempt from PPL's power interruption lists.

"We'd like to be able to provide advance notice to areas where power will be interrupted, but that is not possible because we need to make immediate decisions on where the outages will be," Whitehead said.

"We understand customers' concerns. However, if we do not take this action on behalf of PJM, we could have a much larger-scale problem," he added.

All emergency actions are ordered by the PJM Interconnection and followed by its member utilities in Pennsylvania, New Jersey, Maryland, Delaware, Virginia and Washington, D.C.

Before rotating interruptions, PJM orders other conservation steps, including a voltage reduction and an appeal to customers for voluntary conservation measures. Also, PPL has already curtailed nonessential use of electricity at its facilities.

PPL will continue to keep the public and its customers informed on the status of the situation.

PJM is responsible for the operation of the largest centrally dispatched electric system in North America. It coordinates the delivery of electricity to more than 23 million people in Pennsylvania, New Jersey, Delaware, Maryland, Virginia and Washington, D.C.