A California-style electricity crisis ambushed Las Vegas on Monday afternoon, leaving about 10,000 residential customers without power for 45 minutes until casinos voluntarily reduced their own consumption to make up for the energy shortfall.
The blackout, on a day when temperatures reached 120 degrees on the Strip, was triggered by record demand for electricity, the failure of one local generating unit and a decision by power generators to save electricity for their primary customers instead of delivering it to Las Vegas as promised, said a spokeswoman for the Nevada Power Co.
Operating on about an hour's notice of the pending shortage, the utility asked casino hotels to cut back on unnecessary power, and they responded quickly, said Nevada Power's Glenda McCartney.
"They take a lot of heat [for consuming electricity] but today they came to the rescue," she said. "They were heroes."
Nevada Power said Monday's problems could return today, when the city swells with an anticipated 275,000 visitors arriving to celebrate the Fourth of July.
While the power outage affected some neighborhood stores and knocked out some traffic lights at suburban intersections, there were no reports of serious incidents, and gamblers on the Strip apparently were unaffected.
The major hotel-casinos--each of which consumes about the same amount of electricity as 10,000 homes--responded to the urgent request to conserve power in various ways.
At Caesars Palace and the Las Vegas Hilton, for example, "nonessential" machinery that pushes cooled air through the facilities was turned off, said Debbie Munch, spokeswoman for their parent company, Park Place Entertainment Corp.
At casinos owned by the Mandalay Resort Group, office workers were told to turn off computers and nonessential lighting and to leave work promptly at 5 p.m., Vice President John Marz said.
Both Munch and Marz said they didn't think guests noticed any of the cutbacks.
The utility had braced for a tough day on Monday, after having declared a precautionary "yellow alert" on Sunday.
By 3:15 p.m. Monday, the utility asked local media to put out the word that immediate conservation was needed if the Las Vegas Valley was to escape the day unscathed. But by 4:10, Nevada Power was straining to distribute 4,395 megawatts of electricity--the most in its history--and found itself 50 megawatts shy of demand.
The outages were ordered for mostly residential neighborhoods where there were no malls, casinos, hospitals or other essential services, McCartney said.
As the casinos began cutting back on power, the utility was able to fully restore service by 4:55 p.m., McCartney said.
Nevada Power generates about half of its daily demand and purchases the rest from private generators.
Utility officials had previously boasted, as Californians languished in rotating blackouts, that they had pre-purchased enough power from private sources to see all of their customers through the summer.
On Monday, they were unable to offer a detailed explanation for why Las Vegas was caught short.
"The No. 1 problem was, we have an extreme heat wave blanketing the western United States, and some of our contracts for pre-purchased power were pulled back by the generators for use in their own service territory," McCartney said.
She said she did not know which power generators left the utility short, or where the power ended up going.
"I guess they're allowed to do that, because they did," she said. "They looked to their own customers first."
Relief to Las Vegas also came with scattered, late-afternoon thunderstorms that covered much of the city with clouds and cooling winds.
The utility is braced to face a demand for 4,600 megawatts of electricity later this summer, McCartney said.
Even if the problem worsens, the major casinos are expected to cope by using backup generators, casino officials said.