April 18, 2006

Austin American-Statesman
Heat Forces Power Cuts Across Texas

By TONY PLOHETSKI and CLAUDIA GRISALES , AMERICAN-STATESMAN STAFF

Scorching temperatures sent power usage spiraling throughout Texas on Monday, overwhelming the power grid and triggering mandatory blackouts in Austin and around the state. The Electric Reliability Council of Texas, which runs the state's power grid, said the shortage was caused by record-breaking heat striking at a time when as much as 15 percent of the state's power supply was already off-line for seasonal maintenance. Then four power-generating plants shut down unexpectedly, ERCOT spokesman Paul Wattles said.

So ERCOT ordered utilities to begin reducing the load on the grid before it could appeal to the public for voluntary reductions.

The result was rolling blackouts that sent businesses and homes into darkness, extinguished traffic signals and snarled rush-hour traffic for about two hours Monday afternoon. In Austin, where the day's peak temperature of 100 was the highest ever recorded in April, Austin Energy shut off power to different parts of the city for about 10 minutes at a time between about 4:20 and 6:20 p.m., which sent police officers scrambling to direct traffic at busy intersections.

Austin Energy said about half of its 360,000 customers were affected; two separate power outages in South and Southeast Austin caused by equipment failures lasted several hours. The 100-degree mark at Austin-Bergstrom International Airport broke the date's record high of 97 set in 1987 and the record for any day in April - 99 degrees on April 19, 1951. At Camp Mabry, Monday's high of 99 degrees topped the daily record of 97 set in 1920.

"It's a combination of the fact that April is usually a cooler month, and we had higher temperatures, and we don't have the available capacity that we normally have," ERCOT spokeswoman Dottie Roark said.

Whether the shutdown of the four plants made the difference between having a blackout and business as usual, ''we'll never know for sure,'' Wattles said. He would not identify the plants, saying it's ERCOT's policy not to do so.

The ERCOT grid, which provides electricity to about 80 percent of Texas, typically sees usage of about 40,000 megawatts a day in April, but the state pushed 52,000 megawatts on Monday, Wattles said.

ERCOT said its power grid needed to decrease its load by 1,000 megawatts on Monday.

''The good news is, (the blackouts) worked,'' Wattles said. ''This prevents regionwide outages. It isolates the outages so a few people share the pain to avoid a region blackout like we had in the Northeast in 2003.''

Though the majority of the North American power grid is connected, ERCOT operates as a separate entity. It is connected to outside grids through only three ties that can handle a total of 836 megawatts.

Though that prevents outside blackouts from spreading into the ERCOT grid, as happened to several Northeast grids in August 2003, it also limits the amount of power ERCOT can import on critical days like Tuesday. Austin Energy officials said ERCOT representatives called them just before 3:30 p.m. Monday and said the power supply was "looking a little tight," Austin Energy spokesman Ed Clark said.

ERCOT officials called back less than an hour later and told Austin Energy to begin shedding part of its load, Clark said. Austin makes up 4 percent of the state's power use and was initially told by ERCOT to cut usage by 35 to 40 megawatts, Clark said. The city's peak usage is typically 2,900 megawatts, Clark said.

"Basically we turned off, for the most part, the residential load," he said. "We try to avoid, obviously, any emergency services, and we do not turn off downtown because it is a very complicated system."

"The goal is to leave those customers off no longer than 10 minutes," Clark said.

The only other time the utility has been forced to use rolling blackouts was during an ice storm in the mid-1980s, Clark said.

In Houston, about 68,000 customers at a time were without power, while Dallas-based TXU Electric Delivery rotated outages every 15 minutes in an area stretching from West Texas to East Texas, as far north as the Oklahoma border and as far south as Round Rock.

''They went exactly as we planned, as ERCOT set forward,'' TXU spokeswoman Carol Peters said. ''It's something we practice every year, and it worked exactly as we expected it to.''

The outages were felt all over Central Texas. The Lower Colorado River Authority, one of the state's largest electricity providers, asked the power companies in Central Texas that buy electricity from it to share the pain.

Pedernales Electric, a customer-owned utility that serves 200,000 customers from the Austin area to the Hill Country, got the word from the LCRA about 5 p.m., spokeswoman Anne Harvey said. Pedernales shut off power to about 12,900 members in the Johnson City, Marble Falls, Cedar Park and Canyon Lake areas in 20-minute intervals until 6:30 p.m., she said.

Spokespeople for the two major hospital systems in Austin said their facilities were not affected by the blackouts.

"We did have to go on our generators," said Pam Crowther, spokeswoman for the Seton Healthcare Network, which operates seven acute-care hospitals in Central Texas. Among St. David's HealthCare's four acute-care hospitals in Austin and Round Rock, the South Austin site switched power sources.

But other businesses had to deal with temporary darkness. James Gasaway, an employee at New World Liquor on South Congress Avenue, sat at the door of his darkened business and urged people to come inside. "We're doing good," he said. "We've got a manual cash register."

National Weather Service forecaster Dennis Cook said the record heat would probably subside by Wednesday, when a cold front is expected to drop temperatures into the mid- to upper 80s.