Texas & California summer power supplies tight-NERC

Wed May 30, 2012 12:06pm EDT

* Most of North America has enough power for summer
    * Texas demand is rising faster than power resources
    * California power supply tight until San Onofre back

    May 30 (Reuters) - Most of North America has enough power to
meet peak air conditioning demand this summer, but problems
could arise in Texas and California, the North American Electric
Reliability Corp (NERC) said Wednesday in its summer assessment.	
    NERC is responsible for the reliability of the power grid in
the United States, Canada and parts of Mexico. 	
    The Electric Reliability Council of Texas (ERCOT), which
oversees the power grid for most of Lone Star State, projected
reserve margins would be below targets, NERC said.	
    Power companies use reserves to help keep the lights on in
case demand is stronger than forecast or plants or transmission
lines unexpectedly shut.	
    "With continued growth in peak demand and only a small
amount of new generation coming online, resource adequacy levels
in ERCOT have fallen below targets," John Moura, manager of
Reliability Assessment at NERC, said in a release.	
    "If ERCOT experiences stressed system conditions or
record-breaking electricity demand due to extreme and prolonged
high temperatures, system operators will most likely rely on
demand response and emergency operating procedures," Moura said.	
    He said those procedures may include rotating outages to
maintain the reliability of the interconnection.	
    In California, NERC projected reserves could be tight, but
manageable, especially in the southern part of the state if the
San Onofre nuclear power plant remains offline this summer.	
    The two reactors at the 2,150-megawatt (MW) San Onofre
nuclear plant shut in January and remain out of service due to
problems with the steam generators. 	
    Southern California Edison (SCE), a unit of California power
company Edison International, operates the plant for its
owners SCE, Sempra Energy's San Diego Gas & Electric and
the City of Riverside.	
    SCE cannot say when San Onofre will return to service.
California's power grid operator started preparing for the
possibility of a summer without the nuclear plant a few months
ago.	
    In addition, NERC said Massachusetts could have a problem in
the Boston area if some power plants there receive less
liquefied natural gas (LNG) supplies than needed to run.	
    That possibility may require the region's grid operator, ISO
New England, to implement some proactive measures to keep the
system reliable, NERC said.	
    	
    DEMAND DOWN FOR MOST	
    NERC forecast total peak demand would be about 3,700 MW
lower in the summer of 2012 compared with the same period in
2011.	
    But peak demand in ERCOT was expected to rise 1.7 percent,
the largest increase in North America.	
    NERC said capacity resources have grown across North America
by about 12,310 MW, especially in the Southeast and Northeast
regions.