August 4, 2005

U.S, Canada Grids See Record Power Demand Thursday

NEW YORK -- Citing high heat and humidity, power grid operators in the U.S. Mid-Atlantic and Midwest and in Canada forecast demand for electricity to run air conditioners on Thursday would exceed the record-breaking levels set just last week.

For a second day in a row, PJM Interconnection and the New York ISO forecast record-breaking demand.

Although both grids were close to breaking the records on Wednesday, neither grid actually broke the all-time highs.

Meteorologists forecast high temperatures from Toronto to New York City would reach the mid-90s Fahrenheit (mid 30s Celsius) on Thursday, with the humidity making it feel like more than 100 degrees.

PJM, which operates the nation's biggest power grid for more than 51 million people in parts of 13 Mid-Atlantic and Midwest states, forecast that demand for Thursday would reach 136,387 megawatts, which would break the grid's all-time high of 135,000 set on July 26. On Wednesday, the actual peak reached 134,774 MW.

"We expect to break the record (on Thursday). Even though temperatures in the Midwest will be a little lower, the humidity will be higher in the Mid-Atlantic making air conditioners there work harder," said Ray Dotter, a spokesman for PJM.

The New York ISO, which operates the state grid for more than 19 million New Yorkers, forecast consumers would use 32,500 MW of electricity on Thursday, which would break the grid's all-time high of 32,075 MW which was also set on July 26. On Wednesday, the actual peak reached 31,751 MW.

One MW powers about 800 homes, according to the North American average.


PJM and the New York ISO said power supplies were ample on Wednesday and expected supplies to remain ample again on Thursday.

After sailing through Wednesday without the need to activate emergency power saving measures or call for conservation, neither grid operator said it had taken any step to reduce usage this morning.

Both grids pointed out, however, the unexpected loss of a major transmission line or generating facility could force them to act to reduce the demand for reliability reasons.

In Ontario, the Independent Electricity System Operator (IESO), which operates the province's grid for more than 11 million people, forecast a peak on Thursday of 26,221 MW, which would break the grid's record set earlier this summer.

The Ontario power system has been under more strain this week than the U.S. grids.

On Wednesday, IESO declared a power warning as the supply of reserve electricity ran low, urging customers to reduce "immediately" their power usage.

Although the current heat wave will start to break in the Midwest late Thursday, bringing needed relief to Ontario, the PJM and New York ISO will have to keep watching the power flows for the rest of the week as the Atlantic Coast will not start to cool until Friday night.