Q&A: Power outage

By Curtis Krueger, Times Staff Writer
Published February 27, 2008

Why did a power problem in South Florida affect us in the Tampa Bay area?

The eastern United States electrical grid is interconnected, from Miami to Maine. This way, power companies can buy and sell electricity with each other. But it also means that in rare cases, problems can spread in a domino effect from region to region, as they did Tuesday.

What caused this blackout?

It began with a fire in a malfunctioning switch at a substation in Miami-Dade County, which caused power plants to shut down to protect themselves from damage. Two nuclear reactors and a natural gas plant at Florida Power & Light's Turkey Point power station, 25-miles south of Miami, shut down. Tampa Electric lost two small natural gas plants.

Why didn't the problem stop there?

The plants shut down to prevent possible damage to their generators, explained Thomas Baldwin, professor of electrical engineering at Florida State University. The abrupt shut-downs strained the system. Utility companies say they started to cut off power to customers in selected areas to allow the system to stabilize.

Why didn't the problem spread further?

With fewer customers draining power from the grid, the weakened system could once again produce enough power to supply them, and it was safe to start bringing power generators back on line.

How rare is an event like this?

Very.

"These two coming off unexpectedly like that is extremely unusual," said Bill Whale, vice president of energy delivery for Tampa Electric Co. Nils Diaz, former chairman of the Nuclear Regulatory Commission, said, "We continue to see the need for regional improvements in the electrical distribution system of the United States and Florida." Mayco Villafana, spokesman for Florida Power & Light, said there hasn't been an outage like this since the 1980s.

Curtis Krueger, Times staff writer

[Last modified February 27, 2008, 01:49:05]