About 50 million electricity customers throughout the Northeast and Canada learned that lesson the hard way—an Aug. 14 blackout exposed how vulnerable the nations electric system is to accidental or intentional interruption.
Investigators will mine data from Supervisory Control and Data Acquisition (SCADA) software, much like an airplanes black box, to get a real-time picture of what went wrong. In the meantime, here are the numbers behind the grid:
Energy management systems are primarily used to distribute power across the grid. They arent built to do the computations necessary to adjust the flow of electricity after rapid-fire catastrophic events, says Chanan Singh, head of the electrical engineering department at Texas A&M. "There just wasnt enough time," in August, says Singh. "That has to be done by human beings.
Because of dense populations in cities, power plants need to balance the distribution of electricity between urban areas. If one generator dips its production, others in the power grid offset the fluctuation. This balancing act takes place in nanoseconds.
Singh says overlapping power sources are good "99% of the time," but a sharp drop in power spurs shutdowns.
These systems are designed to balance load, the amount of electricity traveling through the grid, when supply and demand are off-kilter. The system tracks the frequency, voltage and sequence of electricity between two points. If the generators are firing "in-step" in a region, the system adjusts the load on its own. When generators are out of synch, the system alerts operators who decide how to balance the system.
"Its early in the investigation, but its apparent the right information didnt get to grid operators in the time it takes to take corrective action," says Jill Feblowitz, an AMR Research analyst.
The transmission lines of FirstEnergy Corp. of Akron, Ohio, have been singled out as the choke point that triggered the blackout. Early reports indicated a lightning strike may have damaged a generator and key transmission lines in Ohio. FirstEnergy officials, who wont reveal their suppliers, admit that at least one part of their system failed.
"We do know that our alarm-screen function failed," says FirstEnergy spokesman Mark Durbin. "But we cant believe that a problem with our transmission lines could have been the cause of such a widespread problem."
Credit Suisse First Boston analyst James Heckler says blaming FirstEnergy for the mass outage is "premature and likely overstated."
"Theres no standardization of I.T. systems for utility providers," says Scott Castelaz, vice president of corporate development and external affairs at Encorp, a Windsor, Colo., developer of energy management software and hardware. "That becomes a real problem with so many agencies overlapping in densely populated regions."
Analysts say a universal reporting and monitoring system helps operators respond to emergencies. Instead of calling each other by phone when something fails, alerts can come automatically.
"In some ways, its (utility providers) responsibility to connect to each other through their systems," says Feblowitz.
Power companies after world war II built transmission lines and generators in places far removed from cities. While rural residents were thrilled, they couldnt consume the energy at their disposal. More capacity was built to shuttle excess power to metropolitan areas. The electric grid has been neglected ever since.
"Most of the grids infrastructure is more than 50 years old and hasnt been upgraded," says Castelaz. "The power companies are very proud that despite its age, the system still works pretty well most of the time."