Arizona's electrical load is growing more slowly than forecast, leading to delays in high-voltage transmission projects in the state, according to an Arizona Corporation Commission report.
Still, the existing and planned Arizona high-voltage system is adequate to support a robust wholesale market, ACC said in its Biennial Transmission Assessment approved Thursday.
Since the last transmission report was issued in 2012, 10 of 18 planned projects above 345-kV have been delayed by up to three years, three have been delayed "indefinitely" and one has been canceled.
In its last transmission assessment, the commission found that Arizona utilities had canceled six high-voltage projects and 37 were delayed by an average of five years.
The delays are consistent with lower demand forecasts. The 2010 transmission report said load was expected to hit more than 22,000 MW in 2018. Now the forecast for 2018 is slightly below 19,000 MW, according to the report.
"The overall delay of most near-term transmission projects ... is consistent with this shift in the demand forecast," the report said.
At the same time, utility interconnection queues for generation projects have shrunk. The current interconnection queues stand at about 10,010 MW, down from about 18,450 MW two years ago, according to the report, which notes that much of the planned generation is likely targeting California's power markets.
Over the next decade, utilities and others plan to build 60 transmission projects running about 900 miles in Arizona, with a significant share of the mileage related to 500-kV projects, according to the report. "Individually and collectively these projects will improve the opportunity for interstate commerce," the report said.
Through transmission planning, Arizona utilities are addressing concerns raised by the Federal Energy Regulatory Commission and the North American Reliability Corp. about the September 2011 blackout that left more than 5 million without power in the Southwest, according to the report.
