BAGHDAD, Iraq Electricity output has dipped to its lowest point in three years in Iraq, where the desert sun is rising toward another broiling summer and U.S. engineers are winding down their rebuilding of the crippled power grid.

The Iraqis, in fact, may have to turn to neighboring Iran to help bail them out of their energy crisis if not this summer, then in years to come.

The overstressed network is producing less than half the electricity needed to meet Iraq's exploding demand. American experts are working hard to shore up the system's weaknesses as 100-degree- plus temperatures approach beginning as early as May, driving up usage of air conditioning, electric fans and refrigeration.

If the summer is unusually hot, however, "all bets are off," said Lt. Col. Otto Busher, an engineer with the U.S. Army's 4th Infantry Division.

"We're living miserably," said housewife Su'ad Hassan, a mother of four and one of millions in Baghdad who have endured three years of mostly powerless days under U.S. occupation. Her family usually goes without hot water and machine washing, she said, and "often my children have to do their homework in the dim light of oil lamps."

Despite such hardships, Army Corps of Engineers officers regard their Restore Iraq Electricity project as one of the great feats in corps history, along with the building of the Panama Canal a century ago.

Their efforts and related programs, at a three-year cost of more than $4 billion and tens of thousands of man-hours, built or rehabilitated electric-generating capacity totaling just over 2,000 megawatts equaling the output of America's Hoover Dam.

"It's not a disappointment, not in my opinion. We've added megawatts to the grid," said Kathye Johnson, reconstruction chief for the joint U.S. military-civilian project office in Baghdad.

For one thing, deprived areas outside the Iraqi capital are doing better, with a nationwide average of 10 to 11 hours of electricity daily, compared with three to five hours in Baghdad. That represents a reshuffling of priorities from prewar days, when the Baathist government diverted flows from northern and southern power plants to this central metropolis.

Although the U.S. effort helped boost Iraq's potential generating capacity to more than 7,000 megawatts, available capacity has never topped 5,400, held down by plant breakdowns and shutdowns for maintenance, fuel shortages and transmission disruptions caused by insurgent attacks, inefficient production, sabotage by extortionists, and other factors.

Now the U.S. reconstruction money is running out, the last generating project is undergoing startup testing in southern Iraq, and the Americans view 2006 as a year of transition to full Iraqi responsibility, aided by a U.S. budget for "sustainability," including training and advisory services.