Heat wave puts stress on power grid
Irene Wolfe of Westfield, looks at the limited selection of fans in Walmart Tuesday afternoon in Northampton. CAROL LOLLIS Purchase photo reprints »
NORTHAMPTON — People may use enough electricity during this week’s heat wave to topple an all-time record, prompting the company that operates the region’s power grid to urge consumers to voluntarily conserve electricity for the first time since a brutal stretch of hot weather seven years ago.
ISO New England, the Holyoke company that runs the grid in New England, said residents and businesses cranking air conditioners during the heat that is expected to linger through Saturday could push power use to an all-time high. The highest-peak demand is projected for Thursday.
As a result, ISO on Tuesday called on consumers to voluntarily conserve electricity as a precautionary measure to help keep supply and demand in balance. The conservation request urges people to take steps to reduce electricity use through the rest of the week, said Lacey Ryan, an ISO spokeswoman.
“We are forecasting tight conditions on the system, but hopefully these conservation measures will help,” she said.
She said power system resources are currently adequate, but officials are keeping a close eye on supplies as the week progresses.
The record of 28,130 megawatts was set Aug. 2, 2006. Like the current swelter, that early-August heat wave occurred during a regular workweek and resulted in three of the top five power-demand days on record, according to ISO figures.
Several days this week have the potential to crack the top five in electricity use, though power use on Tuesday was less than expected as a result of lower humidity. The region reached 26,228 megawatts, or just outside the top 10. ISO estimates that some 27,000 megawatts will be used Wednesday, followed by an estimated 27,800 megawatts Thursday. In New England, one megawatt of electricity can power about 1,000 homes.
Electricity use grows faster during a prolonged heat wave over several days, especially when temperatures don’t cool off much at night and humidity runs high.
In these cases, houses and other structures start to retain the heat in what’s known as “thermal buildup.” After a few consecutive days in the mid-90s, Lacey said, people’s tolerance for heat wanes, and the sale of air conditioners goes up along with the demand for electricity to run those units.
Temperatures are expected to remain in the mid-90s through Saturday before cooling into the 80s Sunday. Electricity use usually goes down on weekends because many businesses are closed, though demand on Saturday is expected to be high for a weekend day. ISO tracks weekend electricity use differently from weekday use.
Even with the increase demand, ISO expects to have enough power to meet demand. Lacey said the company has yet to resort to special measures, such as bringing in electricity from outside the region or requiring companies that participate in a so-called demand response program to curtail their energy use.
Meanwhile, the two companies that provide power throughout Hampshire County reported that the excessive heat was not causing a problem in their coverage areas.
Western Massachusetts Electric Co. is closely monitoring its system and has additional staff on hand should problems arise, spokeswoman Priscilla Ress said.
“We’ve beefed up personnel and have people on-call,” she said.
Ress said the company also has the ability to do something called “load-balancing,” in which it tracks demands and can shift power to areas that are in short supply so that the entire system stays in balance.
ISO and the utilities offers several measures people can take to conserve electricity. Among the tips are:
∎ Raise air conditioning thermostats by a few degrees and use an electric fan to circulate air. Because air conditioners also remove humidity from the air, they keep people cool even with a higher temperature setting. A suggested temperature range is between 74 and 78 degrees.
∎ Turn off unneeded lights and appliances.
∎ Shut off air conditioners when leaving home for extended periods of time.
∎ Defer laundry and other chores requiring electricity until early morning or late evening hours.
∎ Keep room air conditioners out of the sun and in the shade, and use blinds, shades or drapes to block sunlight during the hottest part of the day.
∎ Cook outdoors.
National Grid keeps its electric system well maintained to help reduce the number of power outages during heat waves and to deal with violent weather that often accompanies hot weather.
“We want customers to be prepared, too,” said Kathy Lyford, vice president of New England operations.
To that end, the company urges people to check on elderly family members, neighbors and others who may need assistance during an outage.