The New York Independent System Operator (NYISO), which operates the state's power grid, said it had asked its biggest customers to voluntarily cut use for the second day in a row.

"We really weren't anticipating the load being this high because the temperatures were supposed to drop," said NYISO spokesman Ken Klapp.

"(Temperatures) have dropped a little but apparently the environment retains the heat and we started off a little hotter this morning than yesterday morning," Klapp added.

Power use in New York State was expected to peak at about 23,785 megawatts yesterday, up from a peak of 23,643 megawatts this week and near the record peak for this time of year of 24,051 megawatts set during a cold spell in January 2000.

NYISO divides the year into winter and summer seasons, with the summer season beginning on May 1.

One megawatt of electricity is roughly enough to power 1,000 homes.

TIGHT POWER SUPPLY

Electricity supplies are particularity thin in April while many utilities take advantage of the typical spring weather and light power demand and take down generation plants for maintenance in preparation for heavy summer use.

New York is struggling to increase its number of power plants to keep up with energy demand and avoid rolling blackouts such as those in California early last summer.

NYISO said in a report in late March that New York urgently needed new generating capacity, "to avoid serious electricity shortages, improve air quality, facilitate economic growth and avert strong upward pressure on prices."

Power use was expected to decrease on Friday as forecasters called for lower temperatures.

In New York City, local utility Consolidated Edison Co. of New York, Inc. (Con Edison) said its system, that serves 3 million customers in New York and Westchester County, was running smoothly with no reports of major outages.

"The system is holding up well," Con Edison spokesman Chris Olert said, adding that the company's system typically peaks in the late afternoon as New Yorkers head home from work and crank up their air conditioners.

LONG ISLAND ALSO SQUEEZED

The state-owned Long Island Power Authority (LIPA) once again pleaded for its 1.1 million customers to cutback on power usage Yesterday.

"We are calling for conservation efforts again today. That is always the case. But we do feel we will have a much nicer margin than yesterday," LIPA spokesman Michael Lowndes said.

Lowndes added that the company was beginning to reach out to large, commercial customers, asking them to voluntarily curtail usage.

Lowndes said that despite being several degrees cooler yesterday and having some cloud cover, the LIPA system's load at midday was actually running higher than this week.

"We are actually running ahead of yesterday's numbers. I think everyone got caught by surprise yesterday and didn't have their air conditioners ready, but today they had them on first thing this morning," Lowndes said.

Yesterday LIPA said it expects to have a reserve margin of about 400-500 megawatts, up slightly from Wednesday's reserve at peak of about 300 megawatts.

Last summer, LIPA came within less than 100 megawatts of running out of supply during a heat wave in August.