18 May 2007 — Electricity capacity margins are expected to be adequate to ensure reliable electric service throughout North America this summer, under normal summer weather conditions, according to Rick Sergel, president and CEO of the North American Electric Reliability Corporation (NERC). However, widespread and sustained hot and humid weather could threaten that reliability. NERC will release this and other conclusions in its 2007 Summer Assessment.
Areas of the greatest concern, which NERC has put on its Summer Watch List, are:
• Southern California, which relies on large amounts of imported power, transported across transmission lines that are heavily loaded during normal operation.
• The Greater Connecticut region, which relies heavily on imported power; although the addition of 200 MW of demand-reduction measures since last summer will help the situation.
• British Columbia, which faces the risk of severe flooding that could damage transmission equipment or require taking equipment out of service.
Areas with improved conditions since last summer include:
• The Southeast, where utilities invested more than $1.21 billion in transmission in 2006.
• Boston, where the ability to import electricity has been boosted by 1,000 MW due to two new 345 kV transmission lines running from Stoughton, Mass., into Boston, which became operational in October 2006 and May 2007 respectively.
• Southwestern Connecticut, which can import 230 more MW of electricity since a 345 kV transmission line from Bethel to Norwalk was put into service in October 2006.
• Texas, which has reduced its transmission congestion, allowing it to reduce the number of less-efficient generating units that must run in tight reliability situations from seven to one.
Several issues highlighted in NERC’s Long-term Reliability Assessment issued in October 2006 are being addressed. The amount of demand represented by customer Interruptible Demand and Direct Control Load Management programs increased since last year by more than 10 percent in Florida, 13 percent in other parts of the southeastern United States, and almost 20 percent in the western United States and Canada. Many regions are studying the interdependence of fuel delivery and reliability, and improving coordination between fuel suppliers and generators.
In Nebraska, all 37 transmission lines damaged in December 2006 ice storms are back in service, six weeks ahead of schedule.