A city task force on energy policy just three weeks ago issued a report that heralded “significant advances” in addressing the city’s energy problems and concluded that the city could push back its need for new energy resources until 2012.

Now, a stifling heat wave that has caused subway failures, flight delays, and power outages across the boroughs is raising questions about whether the city can afford to wait. Con Edison officials have attributed yesterday’s service interruptions to isolated glitches in the utility’s distribution system, not to shortages in power supply, but the city’s struggle with the midsummer heat is casting doubt on the administration’s rosy energy outlook.

The 16-member task force, established by Mayor Bloomberg in July 2003 and chaired by a former Con Ed official, reviewed the city’s progress on 28 recommendations for meeting current and future energy needs, including efforts to increase supply, reduce demand, and improve infrastructure. In its annual status report, the committee found the city had taken positive steps in nearly every area, from adding natural gas capacity to launching energy efficiency initiatives to completing infrastructure master plans for Hudson Yards and Lower Manhattan.

Citing a study by Con Edison released in December 2005, the task force’s chairman, Gil Quiniones, said in a press release issued by the mayor’s office with the report, “New York City’s need for additional energy resources to meet load growth and reliability requirements has been deferred to 2012, which will allow the city to plan for its future needs in a thoughtful way.”

In 2004, the task force found that the city would need about 25% more electricity by 2008. Three weeks ago, the panel concluded that measures to save energy and improve production had lessened the urgency.

Industry and city leaders used the season’s first heat wave to call for the passage in the state Legislature of a renewed “siting law,” which could pave the way for more power plants to serve the five boroughs.

“This is a stark reminder that New York City and state need to get their act together with regard to renewal of the siting law and getting additional generation capacity,”the president and chief executive of the Partnership for New York City, Kathryn Wylde, said. Ms. Wylde serves on the mayor’s energy panel.

Con Edison officials said the utility reported no supply shortages and that yesterday’s outages were caused by isolated equipment problems with underground cables. “Even if you had more power plants today, you could still have problems,” a spokesman, Michael Clendenin, said.

Task force members cited that finding in defending their report, emphasizing that supply and distribution were two separate issues when it comes to electricity. In an interview yesterday, Mr. Quiniones, who is the senior vice president of the city’s Economic Development Corporation, sought to clarify the administration’s position on energy. “We are not advocating that we become complacent,” he said. “You never want to see even short-term disruptions. The key is to keep them contained and to restore power quickly. Con Ed is working around the clock to make that happen.”

For city and Con Edison officials, yesterday’s message was that, to a certain extent, power outages are a fact of life during periods of extreme heat.”Even the most reliable system is more susceptible to disruptions during heat waves,” Mr. Quiniones said.

The state’s Independent System Operator reported a record peak demand for electricity on Monday, with 32,624 megawatts expended between 4 p.m. and 5 p.m. Yesterday’s total was 32,060 megawatts during the same hour.

Critics of the administration’s energy policy say not enough is being done to improve the city’s aging power infrastructure, leading to routine outages during hot weather and recent incidents in which people and their pets have been shocked by stray voltage from under the sidewalk.The owner of TransGas Energy, Adam Victor, said yesterday’s outages “highlights the pathetic indifference that has been given to energy by the city administration.”

Mr. Victor wants to build a 1,100-megawatt power plant along the waterfront in Williamsburg, but his project has faced opposition from the Bloomberg administration, which says it conflicts with its plans for a 28-acre park as part of a rezoning initiative for the neighborhood. Mr. Victor’s revised application is now before a state judge in Albany. A ruling is not expected before next year.

To Mr. Victor, the city’s delay in adding to its power supply constitutes a risk with potentially dire economic consequences. If companies can’t rely on energy stability during summer in the city, they will move elsewhere, he said. “They don’t want to have to worry that they won’t be able to compete with global markets four months out of the year,” Mr.Victor said.

The heat wave also roused the political ire of candidates running for office this year. The Republican candidate for governor, John Faso, issued a statement calling for lawmakers to pass the state’s power plant siting law, which expired in 2002. The Assembly and the Senate have not agreed to renew the provision, known as Article 10, which outlines a timely process for building power plants in the state. The Democratic frontrunner, Eliot Spitzer, did not release a statement, but he has previously called for the state to “immediately” pass the siting law.