* New all-time power demand record at 98,576 MW
* Grid met peak demand with little problem
By Scott DiSavino
July 25 Demand for electricity in the U.S.
Midwest reached record breaking levels on Monday as homes and
businesses across the region cranked up their air conditioners
to escape a heatwave, the operator of the Midwest power grid
said on Wednesday.
The Midwest Independent Transmission System Operator (MISO),
which operates the power grid in 11 U.S. Midwest states and the
province of Manitoba in Canada, said in a release that
electricity usage reached 98,576 megawatts (MW) on Monday
That just broke the previous all-time record of 98,526 MW
set in July 2011.
For a factbox on U.S. and Canadian record peaks, see
To help keep consumers' air conditioners humming on Monday,
the MISO did not have to take any steps that customers would
The MISO did, however, tell generators and transmission
owners not to conduct any unnecessary maintenance during the
heatwave, which is a common grid management step also used by
other U.S. power system operators during hot weather.
Temperatures in Chicago, the biggest city in the U.S.
Midwest, reached 98 degrees Fahrenheit (37 degrees Celsius) on
Monday, but dropped to 88 F on Tuesday, according to
On Wednesday, the mercury was expected to return to the 90s
again in the Windy City, topping out at about 95 degrees before
dropping back to near normal levels in the mid 80s again on
Thursday, AccuWeather.com said.
The MISO forecast that demand for power on Wednesday would
only reach about 93,000 MW as thunderstorms start to cool parts
of the region.
The biggest utilities in the MISO include units of Duke
Energy Corp, Xcel Energy Inc, Ameren Corp
, Berkshire Hathaway Inc's MidAmerican Energy,
DTE Energy Co and CMS Energy Corp.