August 16, 2013

TEN YEARS LATER, how have we avoided another mega-blackout?

While power didn’t go out until close to 4:00pm Eastern time that day, the roots of the massive chain reaction started two and a half hours earlier, when the Eastlake 5 power plant in northern Ohio lost one of its generators. Shortly thereafter, the power company’s energy management system went down, leaving them in the dark, so to speak, about other trouble that was brewing. Between 3:05 and 3:41, the company’s power-transmission lines—sagging from the August heat—came into contact with trees that should have been pruned. That sparked a massive short that further choked off the power supply to northern Ohio.

The result was a massive power surge as electricity from the interconnected grid tried to flood back into Ohio. The grid tripped off—as intended—to prevent overload damage. But then it sparked an irreversible surge-and-trip cascade across much of the Northeastern U.S. According to a report by a Canadian-U.S. task force, 265 power plants went down, many within a matter of minutes of each other.

So why haven’t we had a major power outage since then? For one thing, power companies are now forced to prune their trees thanks to the Energy Policy Act of 2005. But the other major factor is a technological advance. According to Matt Wakefield of the Electric Power Research Institute, most power transmission companies have now installed high-tech synchrophasors, which allow them to detect problems in transmission lines and reroute electricity around trouble spots. The synchophasors work by giving real-time feedback on power flows and voltage and transmitting the data back to power companies.

“While we will always have local and regional power outrages because of things like weather,” Wakefield says, “these synchrophasors mean that these rolling blackouts that can affect large regions of the country at once are much less likely.”

Nevertheless, those local and regional outages are growing increasingly common.

I’m still thinking about adding a whole-house backup generator. Kohler, or Generac?