Texas imposes rolling blackouts
The power grid operator imposed rolling blackouts as cold weather swept across the state, leaving nearly 3 million homes temporarily without electricity.
Wed, Feb 02, 2011 at 12:21 PM
WINTER WEATHER: One of the largest winter storms since the 1950s is affecting 30 U.S. states with snow, sleet, freezing rain and rain. (Photo: ZUMA Press)
HOUSTON - The Texas power grid operator on Wednesday imposed rare rolling blackouts as frigid weather swept across the state, leaving nearly 3 million homes temporarily without electricity.
After the cold snap caused 7,000 megawatts worth of power plants to shut down, the Electric Reliability Council of Texas, the grid operator for the second most populous state behind California, declared an energy emergency.
ERCOT called on state energy suppliers to cut about 4,000 megawatts worth of power demand in the early hours of the day — equal to about 2.9 million homes.
The grid operator reduced that call to about 3,000 MW by mid-morning as some generation returned to service.
"We expect the rolling outages to continue until a sufficient amount of generation is back online," ERCOT said in a statement. "We are continuing the appeal for energy conservation."
The blackouts left homes dark and without heat for up to an hour, caused some schools and businesses to shut and spurred traffic snarls as some traffic lights stopped working.
There was no sign of significant outages at Houston's massive "refinery row" complex, which comprises about 13 percent of U.S. refining capacity.
Shell Oil Co said severe winter weather triggered a malfunction in fuel production units at its 329,800 barrel-per-day joint-venture refinery in Deer Park, Texas.
"Houston faces rolling blackouts, which should be disruptive to residential users. This is not likely to have any major effect on the oil industry," Mark Routt, oil engineer and consultant at KBC in Houston told Reuters.
Refineries and other critical infrastructure have separate power supply agreements with utilities and are less susceptible to interruptions than residential or commercial customers.
In Houston, the state's most populous city, power supplier CenterPoint Energy, started 45-minute "controlled rolling outages" at about 5:45 a.m. local time, affecting about 330,000 customers on a rotating basis.
"These controlled rolling outages are planned emergency measures designed to avoid potentially longer, and more widespread power outages," CenterPoint official Scott Prochazka said in a statement.
American Electric Power Co and PNM Resources also imposed rolling blackouts on their Texas customers.
Weather-related unit outages caused hourly wholesale power prices in Texas to soar 60-fold to $3,000 per megawatt-hour, up from about $50 where they usually trade. That's comparable to about $3 per kilowatt-hour for residential users, though most Texas home-owners have long-term power deals with suppliers that protect them from short-term price spikes.
Wholesale power for Thursday delivery traded in the $325 range, up from about $70 for Wednesday, as cold weather was expected to persist until Friday.
ERCOT forecast peak demand would top 55,000 megawatts on Wednesday and 57,000 MW on Thursday before dropping to about 47,000 MW on Friday.
That is still well below the grid's 2010 summer peak of 65,715 megawatts.
Power emergencies in Texas are rare — in February 2008 cold weather coupled with dwindling wind supplies triggered a power emergency that caused ERCOT to cut deliveries to some large industrial customers.
Texas saw rolling blackouts in April 2006 due to soaring heat and high demand for air conditioning.
ERCOT serves about 22 million customers in the Lone Star State, representing 85 percent of its electric load and 75 percent of its land.
(Additional reporting by Scott DiSavino, Joe Silha and Josh Schneyer in New York; Editing by Lisa Shumaker)
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