July 31, 2006

Heat wave pushes east, testing power grids

By Eileen O'Grady and Bernie Woodall

LOS ANGELES (Reuters) - A punishing heat wave pushed power
use in the U.S. Midwest to record highs on Monday and looks to
do the same on Tuesday and Wednesday in New York and the
Mid-Atlantic, power grid officials said.

The eastbound heat wave will cause temperatures in Eastern
cities to the upper 90s to over 100 degrees Fahrenheit on
Tuesday with humidity making it feel 110 degrees F.

"Tuesday will turn viciously hot across the Northeast,"
said forecaster AccuWeather. "The nasty heat that has been over
the Plains the past few days is in the process of heading

Power grids in the Midwest, New York and the Mid-Atlantic
are expected to strain but not break during the next two days
of high summer heat, officials at the various grids said. But
unexpected major power plant outages or transmission line
breakdowns could cause rolling blackouts.

The Midwest power grid operator said the 15-state system
set a high on Monday of 136,520 megawatts, up 2.9 percent from
the previous record set July 17.

In general, a megawatt can power 800 homes.

The Midwest ISO record may fall on Tuesday as the heat wave
is not expected to break there until Wednesday, said Carl
Dombek of the Midwest Independent System Operator.

The biggest power grid in the United States, PJM, expects
to set a record for power use on Tuesday, at about 143,000
megawatts, said Ray Dotter, PJM spokesman. That would eclipse
the mark set July 17 of 139,746 megawatts.

PJM handles power delivery to about 51 million including
New Jersey, Pennsylvania, Ohio and some Midwestern and
Mid-Atlantic states.

"We are not expecting any serious situations Tuesday," said
Ray Dotter, spokesman for PJM. "The system looks OK. We are
putting out a call for voluntary conservation Tuesday not
because of anticipated problems but it's hot and we'd like to
have as much of a cushion as we can have."

The New York power grid operator, which manages mainline
flow of electricity for the state's eight utilities, is calling
for record power use on Tuesday and even more consumption on

The heat wave abated by late last week in California but
not before some 150 died as a result of the heat. Most of those
who died were elderly and in an area called the Central Valley
in the central part of the state.

Good news for electricity delivery is that the heat wave is
expected to last only through Wednesday.

The longer a heat wave lasts, the more risk there is that
power plants or power lines can fail, Dombeck said.

In New York, the grid operator said the most concern of
outages is in the southeastern part of the state including New
York City and Long Island.

Increased power use is expected to increase earnings for
big U.S. utilities by 19 percent in the third quarter, analysts
said on Monday.

(Additional reporting by Scott DiSavino in New York)