Arizona Corporation Commissioner Kris Mayes said Monday she wants the state's electric utilities to push harder to develop renewable energy sources such as solar, wind, geothermal and biomass.
Arizona's utilities are already required by the commission to acquire 15 percent of their electricity from renewable sources by 2025, but Mayes wants the regulators to expand that to 25 percent by 2025.
"It's possible, and it's necessary," she said. "The utilities are already going to exceed the 15 percent requirement."
Speaking at a Sustainability Town Hall at the SkySong innovation center in Scottsdale, Mayes drew applause from the standing-room-only crowd when she said she looked forward to the day when a visitor flying into Phoenix Sky Harbor International Airport "will see as many solar panels on the rooftops as swimming pools in the backyards."
Mayes said she plans to write a letter to other members of the commission within a few weeks proposing that the mandate on renewable energy sources be increased.
She said, however, that it could take a year or longer for the five-member commission to agree on such an increase. And the fate of the proposal probably would depend on the attitude of the three new commissioners who will be elected in November.
Some candidates have questioned the mandate, saying it will increase consumers' electric bills.
John LeSueur, policy adviser to Gary Pearce, the only member of the commission other than Mayes who will remain on the panel next year, said Pearce has not spoken with Mayes about her proposal. But he said Pearce may question the idea of picking a different number.
"Why not 45 percent instead of 25 percent?" LeSueur said. "He believes there is justification for intervening in free markets to benefit renewable energy, but the question is how to do it."
Barbara Lockwood, manager of renewable energy for Arizona Public Service Co., indicated that the utility might be able to meet an increased standard.
"We have always looked at (the 15 percent requirement) as a floor," she said, adding that the utility is about three years ahead of schedule for meeting the requirement.
APS currently obtains about 2 percent of its electric supply from renewable sources, which will increase to 5 percent in 2012 when the 280-megawatt Solana solar thermal power plant is expected to be operating near Gila Bend, she said.
It would be the world's largest solar power plant if in operation today.
She added that APS, Salt River Project and other utilities are expecting to announce a second solar power project of similar size in the near future.
But participants said the Solana plant and other major solar projects are contingent on the U.S. Congress extending federal solar tax incentives that expire at the end of this year.
The U.S. House of Representatives has approved a bill that would extend a 30 percent investment tax credit for solar energy property for six years, until 2014. Also, the bill would extend a residential solar property tax credit for six years and extend a research and development tax credit for one year.
The U.S. Senate is considering a companion bill.
Rep. Harry Mitchell, D- Ariz., is optimistic that lawmakers will get the tax credit approved and sent to President Bush's desk before the end of the year.
But he added that disagreements over details, such as how to pay for the lost revenue, are slowing progress.
"Everyone wants an extension. The question is, in what form?" he said.