But all parties involved said much of that could go out the window if the state has a bad wildfire season and the fires threaten transmission lines coming to the Valley from the northern part of the state.
"We have enough reserve resources to handle most anything," said Tom Glock, manager of power operations for Arizona Public Service Co., during an Arizona Corporation Commission hearing on summer preparedness.
APS is forecasting that its peak load will be about 1 percent below last year. Phoenix's largest electric company says it has nearly 18 percent in operating reserves above the projected peak load.
Salt River Project predicts that its peak load will be about one-half of 1 percent more than the peak load of last year, and that its operating reserves are 14 percent above the projected peak load.
An above-average wildfire season has been predicted for this season as the state's drought persists.
Commissioner Mike Gleason said that the area of the state's largest-ever wildfire, Rodeo-Chediski, near Heber and Show Low, is a threat again five years after the fire because of the growth of vegetation.
Steve Bischoff, an APS general manager, said the utility has been working feverishly in conjunction with the National Forest Service to do clearing in particularly sensitive areas of transmission lines.
"We're aware that there's another high-risk fire season coming up, and this is a serious statewide concern," Bischoff said. APS also has a planned outage at Unit 1 of Palo Verde Nuclear Generating Station in June.
Global warming also was a repeated theme in the hearing.
Commissioner Jeff Hatch-Miller wondered how much the expected clampdown on carbon emissions would have on Arizona utilities' ability to produce and purchase power.
That impact would be greatest on Tucson Electric Power. The utility receives 69 percent of its electricity from coal-fired sources.
"We were at a 98 percent base in coal, but we've reduced that by getting natural gas in the mix," said Leland Snook, general manager of TEP's wholesale energy supply.
Commissioner Kris Mayes expressed concern that both APS and SRP had underpredicted what peak demand would be for the past three years, SRP by 380 megawatts last year and APS by 330 megawatts.
"You keep consistently underforecasting the demand. Are we growing so fast that the utilities can't predict demand anymore?" Mayes said.
Representatives of all the utilities said the models used to make predictions could not project the record Arizona heat last July.