Barring any disaster such as forest fires that shut down several high-voltage transmission lines, the Valley should have plenty of electricity to get through this summer, according to Arizona utilities and regulators.
Officials of Arizona Public Service Co. and Salt River Project said they have “healthy” reserve power supplies available above the anticipated peak demands on their systems.
The summer months of June, July and August are always the periods of top demand for electricity in Arizona because of use of air conditioners.
“We feel confident in our electrical system heading into the summer,” said Steve Bischoff, general manager of construction, operations and maintenance for APS.
But regulators also warn that consumers shouldn’t feel too complacent. “It’s becoming increasingly clear that Arizona’s growth and weather are very unpredictable,” said Commissioner Kris Mayes. “Utilities have done a pretty good job of building power lines and generating plants, but it’s getting hotter every summer and Arizona is growing more every year. Each individual will hopefully consider ways to use less energy.”
Summer power has been a problem in the past for the Valley, due to unexpected events. In 2004 a fire at a substation in the West Valley caused utilities to urge customers to cut back on their use of electricity. Voluntary cooperation prevented blackouts, but the margin was thin.
Since then utility officials say they have improved the power grid to add more capacity and redundancy.
Bischoff said APS spent more than $400 million on transmission and distribution infrastructure in 2006, including 10 substations and nearly 1,000 miles of transmission and distribution lines.
SRP has added five substations, nine transformers and other improvements to its system in the past year, said Mike Hummel, SRP’s manager of supply and trading.
Also, the two utilities are expecting a return to more normal summer temperatures this year after an unusually hot 2006, which they anticipate will hold down the peak demand.
APS expects peak use of 7,542 megawatts on its statewide system this summer, which is actually down from a peak load of 7,652 megawatts last year.
The utility said it has the ability to supply a peak load of 8,601 megawatts, giving it a reserve margin of 14 percent, with further supplies available under long term contracts, if necessary.
SRP is forecasting a peak load on its system of 6,627 megawatts this year, up only marginally from the peak of 6,590 last year.
It has resources totaling 7,539 megawatts, a 14 percent reserve. Hummel also said SRP could purchase addition power above its reserve total on the wholesale market.
Commissioner Jeff Hatch-Miller agreed that power supplies should be sufficient this summer, but he worries about the future. As Arizona continues to grow and demand more electricity, no new power plants are under construction, he said.
“We have quite a bit of excess now, but in five years-plus we are looking at break even,” he said. “We have a lot of work to do in 2007 to prepare for that day.” Because of environmental concerns, he said, Arizona will have to look to clean, renewable technologies such as geothermal and wind power. Eventually the state will have to consider expanding its nuclear capacity too, he said.