The city is bracing for near record-breaking energy demand on the second day of sweltering 90-degree temperatures.
Con Edison said peak energy usage Thursday was 12,414 at 5 p.m. The record set last summer of 13,189 megawatts.
There have been scattered outages since the heat began, and expects those to continue throughout the heat wave. As of Thursday afternoon, there were about 470 customers without power, mostly in Park Slope, Brooklyn.
LIPA reports 61 scattered outages affecting about 3,000 customers.
In New Jersey PSE&G is reporting only about 100 scattered outages.
Con Ed plans to preemptively reduce voltage in some areas to take pressure off the network.
"Some may notice differences in the way their lights and appliances run but many do not notice anything, especially when we reduce voltage by only 5 percent," spokesman Allan Drury said.
Drury said some people with older incandescent light bulbs may notice a flicker or dimming, and those with older appliances may experience that the motors run slower, but the majority of customers won't notice any difference in service.
To reduce energy, the company is asking customers to set air conditioners at 78 degrees, have clean filters and to close doors to rooms that aren't being used.
Meanwhile, lawmakers are reminding store owners to keep their doors closed while air conditioners are running. In 2008, the city officially passed a measure forbidding shops from running their air conditioners with doors wide open.
“Nobody wants a brown-out,” said bill co-sponsor Gale Brewer. “Nobody wants to find out in the morning or at night that their electricity is not working because the grid is overloaded; so people should understand in stores that they are a part of a larger process, it's not just their store.”
The law, however, only applies to any store with at least 4,000 sq. feet and to smaller stores that are part of a chain with a least five shops in the city.
The city began enforcing the law in 2010. A first offense brings a warning and a second carries a $200 fine.
According to Consumer Affairs, 348 warnings were issued and only 25 citations were handed out from 2010 through May of this year.
Anyone experiencing an outage should call Con Ed at 1-800-75-CONED or visit their website at coned.com.
Eddie Robinson contributed reporting.