By Brad Foss
The Associated Press

WASHINGTON - The industry group that monitors the nation's electric grid expects the system to perform adequately this summer, although it warned that "uncontrolled blackouts" were possible if power providers fail - as they did last August - to comply with reliability standards.

The North American Electric Reliability Council also warned Tuesday that the increasing volume of power trading that goes on in deregulated markets can cause "volatile and unpredictable flow patterns (that) can pose significant challenges for transmission system operators."

Significant vulnerabilities remain even though grid operators have upgraded technology and become better coordinated since last Aug. 14, when 50 million people in eight states and parts of Canada were thrust into darkness.

Most distressing, industry experts said, is that nine months after the largest blackout in U.S. history the nation's reliability standards remain voluntary.

A proposed energy bill that stalled in Congress would make these standards mandatory. In the meantime, the Federal Energy Regulatory Commission is going ahead with a plan to tie compliance with NERC's reliability standards to utilities' ability to collect transmission tariffs from customers.

NERC's emphasis on reliability standards is consistent with the findings of the joint U.S.-Canadian task force that investigated last summer's blackout. The task force concluded that a significant cause of last summer's blackout was the power industry's disregard of rules intended to ensure the reliable flow of electricity.