Heat continues to test East Coast power grids

NEW YORK (Reuters) - U.S. East Coast power grid operators said they had enough electricity to keep air conditioners running Tuesday as a heat wave continued to grip the region.

Meteorologists forecast the heat and humidity would again make it feel like more than 105 degrees (Fahrenheit) Tuesday in the big cities from Connecticut to Virginia, including New York, Philadelphia and Washington, before highs drop into the 80s on Wednesday.

The grid operators forecast demand Tuesday would top the highs for the summer that were hit Monday, but would not reach record-breaking levels.

The New York ISO, which operates the grid for nearly 20 million New Yorkers, did not have to take any steps to keep the lights on Monday and did not expect to take any steps Tuesday, a spokesman said.

In fact, none of the grid operators has yet taken any steps to reduce customer usage or shed load during the heat wave.

However, the Midwest ISO, which operates the grid for 36 million people from Montana to Pennsylvanian, kept an emergency alert in place for the FirstEnergy Corp. system in Ohio due to some unplanned generation outages and the continued heavy air conditioning demand.

A spokesman for FirstEnergy said Tuesday its Ohio system was in good shape with extra generation they had on Monday still available.

Meteorologists forecast temperatures in Cleveland would reach 95 degrees Tuesday afternoon, before thunderstorms march across the state, dropping high temperatures into the 70s for the rest of the week.

As temperatures decline across its territory, the Midwest ISO forecast demand Tuesday would decline from Monday.

Still, some power companies, including Exelon Corp.'s PECO in Philadelphia and Consolidated Edison Inc. in New York City, urged customers to conserve power by raising air conditioners thermostats and turning off unnecessary lights and appliances, among other things.

A spokesman for Con Edison, which serves some 3.2 million customers, said the utility had fewer than 200 customers out of service, not necessarily due to the heat.

Later in the day, the grid operators, or some utilities, may activate demand-side management programs that pay customers -- usually commercial and industrial businesses that use a lot of power -- to reduce the amount of electricity they consume.

Customers can sign up for demand-side management programs that provide lower cost power for agreeing to reduce usage when called upon for reliability reasons, or voluntary programs that provide monetary incentives to reduce usage when prices or demand reach certain triggers.