With three incumbents set to depart, the race for the Arizona Corporation Commission this year is shaping up as a free-for-all.

Nine contenders have announced their candidacies for the three seats opening up on the panel, which regulates electric, water and other utilities in Arizona and plays a major role in setting energy policy. More may jump in.

In addition to the large number of candidates, a major issue may generate more than the usual interest in this year's contest - renewable energy. The incumbent commission is requiring Arizona electric utilities to obtain 15 percent of their electricity from renewable sources such as wind, solar and geothermal by 2025. Several candidates want to rescind or modify that rule, saying it will drive up the price of electricity for consumers.

Incumbents Jeff Hatch-Miller, Mike Gleason and Bill Mundell, all Republicans, are completing their second terms this year and must resign. Eight Republicans and one Democrat so far have said they want to replace them.

The GOP candidates are divided into two three-member teams, and two aspirants are running solo.

Mesa resident Rick Fowlkes, a former Libertarian Party candidate for the commission; Joe Hobbs, a telecommunications technology specialist from Avondale; and Keith Swapp, a former U.S. Bureau of Reclamation executive from Buckeye, are running as a libertarian-oriented Republican team.

They favor rolling back the renewable energy requirements and support more competition in the utility industry.

Fowlkes calls the renewable energy mandate "nonsense" and said a more sensible approach would be tax incentives to encourage utilities to use alternative energy.

Another three-member Republican team is composed of state Reps. Marian McClure of Tucson, Bob Robson of Chandler and Bob Stump of Peoria.

They are touting their experience in the Legislature in consumer protection, business innovation and infrastructure development.

Robson is a former vice-mayor of Chandler.

Also running for the commission are Republicans John Allen, a former state representative from Scottsdale, and Barry Wong, a member of the commission in 2006 and currently a member of the Arizona Power Plant and Transmission Line Siting Committee.

Allen said his major goal if elected would be to control upward pressure on utility rates.

Wong was a member of the commission when the renewable-energy mandate was adopted, and he pledged to continue to support "clean renewable energy as part of diverse energy production."

The only Democrat to announce so far, Flagstaff City Councilwoman Kara Kelty, said she wants to "make Arizona the leader in sustainable energy policies and renewable energy standards."

Discussions are under way to determine if more Democrats are interested in running, said Emily Bittner, spokeswoman for the Arizona Democratic Party.

Gary Pearce, an incumbent member of the commission whose seat is not up for election this year, said so many candidates are attracted to the commission because of the extensive powers given to it by the Arizona Constitution.

"It's stuff that's really important for the growth of Arizona," he said.

The party nominees will be determined in the Sept. 2. primary election, and the winners will be selected in the Nov. 4 general election.