Since the blackout on Aug. 14, 2003, which affected 50 million people in the Northeast, Midwest and part of Canada, federal regulators have approved standards for upkeep of the power grid. And utilities have new systems to monitor the network.
"I can definitively say the events that led to the 2003 blackout are much less likely to occur," says Rick Sergel, head of the North American Electric Reliability Corp. (NERC), which enforces the new rules.
But there are still concerns:
The United States still doesn't have enough power plants and transmission lines to meet surging demand for electricity, which strains the grid, says Branko Terzic, an energy adviser for Deloitte Services and a former Federal Energy Regulatory Commission member. Utilities have canceled plans for dozens of coal plants amid global-warming concerns; environmentalists have opposed new transmission lines.
While new computer systems better monitor network glitches, "The grid doesn't have a brain" that "makes sense of it in a holistic way" and responds, says Roland Schoettle, CEO of Optimal Technologies.
Joseph Kelliher, FERC chairman, says cyberterrorism is a threat and that his agency needs authority to prevent it without publicizing its measures.
The 2003 outage began when several transmission lines owned by FirstEnergy in Ohio automatically shut down because they came too close to trees. That caused electricity to be rerouted to other transmission lines, which, in turn, overloaded and failed. Since power plants and high-voltage lines must be in balance, the failures caused a ripple effect that shut down generators and lines across eight states. A computer bug kept FirstEnergy from identifying the problem.
In 2005, Congress gave FERC new authority to set standards that, among other things, require utilities to trim trees to prevent them from contacting power lines, and to ensure that operators are trained and certified. NERC can fine companies up to $1 million per day per violation.
Also, new computers let regional grid operators monitor small changes in power flow. The Midwest Independent System Operator and PJM Interconnection, which oversee regional grids, say systems predict the results of line failures and stop outages by adjusting power. FirstEnergy spent $20 million on computers.