New York’s Central Park is heading toward its warmest July on record after two heat waves this month, the National Weather Service reported. Extreme heat pushes aging power systems to their limits, increasing the odds of breakdown, according to grid monitors.

“The grid system was built a long time ago, and the population has increased dramatically across this part of the country, and energy demand has gone up accordingly,” said Jim Rouiller, a senior energy meteorologist at Planalytics Inc. in Berwyn, Pennsylvania. “July may not be the top, but it is going to be in the top five, and this is over 130 years worth of observation, so it is outstanding heat.”

In August 2003, bad equipment and operator error at an Ohio power plant triggered an outage that left about 50 million people in eight U.S. states and Ontario without electricity for as long as four days, according to a U.S.-Canada Power System Outage Task Force report issued in 2004.

“Weather was not the root cause, but it was a contributing factor,” said Jay Apt, executive director of Carnegie Mellon University’s Electricity Industry Center in Pittsburg. “On days of high demand, the system is closer to the edge than it is on days of low demand.”

Monthly Average

The average monthly temperature in Central Park has been 81.6 degrees Fahrenheit (27.6 Celsius) so far, warmer than the record set in July 1999 of 81.4, said Matt Scalora, a weather service meteorologist in Upton, New York.

The higher-than-normal temperatures have driven up electric power use around the U.S., including in New York, which recorded its third-highest hourly peak load of 33,542 megawatts on July 6 when temperatures reached a record 103 degrees in Central Park.

The highest hourly peak load was 33,939 recorded on Aug. 2, 2006, according to a statement by New York Independent System Operator in Rensselaer, New York, a not-for-profit corporation responsible for operating the state’s bulk electricity grid.

Just before the 2003 outage, peak demand in New York was 28,634 megawatts, said Kenneth Klapp, a spokesman for the ISO. The failure knocked 22,934 megawatts offline and left 5,700 still going to customers. Load levels for New York’s ISO had actually gone down in 2003 from a year before, according to the company’s annual report.

In 2003, New York had about 35,800 megawatts of installed capacity, Klapp said. For 2010, it has 38,970, according to an ISO statement. More than 7,823 megawatts of capacity has been added since 1999, Klapp said.

A heat advisory was issued for New York City Monday, where the temperature in Central Park was 90 at 3 p.m. after three straight days above 90, according to the weather service. The definition of a heat wave is three consecutive days with temperatures of 90 degrees or higher.

Conservation Urged

High temperatures prompted Consolidated Edison Inc., New York’s power utility, to ask customers to curb electricity use, and the Suffolk County Water Authority, the largest on Long Island with 1.2 million users, to ask for water conservation.

The above-normal temperatures have been driving coal and natural gas consumption as electric demand jumps when people turn on fans and air conditioners.

Earlier this month, a heat wave gripped New York and the rest of the U.S. Northeast, driving temperatures into the 100s for several days and setting daily records across the region. The Central Park readings came within 3 degrees of the city’s highest temperature on record, 106 on July 9, 1936, according to the weather service.

(Source: Bloomberg News)