In a debate this week, the three Democrats and three Republicans running for the Arizona Corporation Commission sparred over the agency’s role in lowering energy costs for Arizona residents and promoting the use of more renewable energy across the state.

The Democratic candidates vying for the commission’s three open seats — Ylenia Aguilar, Joshua Polacheck and Jonathon Hill — argued the current Republican majority has been too deferential to utilities seeking rate increases in recent years, including approving an 8% rate increase for APS customers earlier this year.

“They have not seen a rate increase that they didn’t embrace,” said Polacheck, a former foreign service officer with the U.S. Department of State.

But the Republican candidates, including incumbent Commissioner Lea Márquez Peterson, said the reality of the situation is more complicated than that, pointing out that the commission actually reduced APS’ rate increase request by $200 million.

Márquez Peterson also cited a Wallethub study that showed Arizona has some of the lowest energy prices in the country and promoted other policy decisions made during her tenure.

“Since serving as chairwoman of the commission, I passed a code of ethics which asked folks and promoted leading with integrity, also utilizing the clean elections program to keep utilities out of our races,” she said.

Polacheck said APS and other utilities are still posting high profits as Arizonans see their utility rates increase.

“I think what you’ve just heard tonight is the inability of our opponents to look you straight in the eye and say what you’re paying is too much,” Polacheck said. “That we should not be seeing record profits with our utilities while we’re paying record prices every month with our electricity and gas bills.”

Republican Rachel Walden, a member of the Mesa Public Schools governing board, countered that point by claiming much of those profits go to pay off debt accrued by the utilities in between rate increase requests.

“A lot of our utilities have been dragging these expenses around for years,” she said. “Now it’s time to pay the bill.”

The candidates also debated the commission’s role in pushing utilities to adopt renewable energy goals.

Márquez Peterson, who earlier this year voted to repeal renewable energy standards adopted over a decade ago, said Arizona needs a diverse mix of energy sources, including solar and fossil fuels, to meet growing demand, suggesting relying too heavily on any single source could put Arizona at risk of a grid failure.

“We need to prepare for that energy demand and that is why energy reliability needs to be our number one factor,” she said. “We need to realize that if we had rolling blackouts like California, it could be a life or death situation in Arizona.”

She argued the commission should not impose specific renewable energy thresholds but said she supports voluntary goals adopted by organizations like APS and SRP.

Fellow Republican Rene Lopez, a former Chandler city councilman, said the free market — not the commission — should determine the energy mix used by Arizona’s utilities.

But Hill, an engineer with ASU’s Mars Space Flight Facility, said Arizona’s existing utilities already operate outside of the free market.

“These utilities are monopolies,” he said. “They are not subject to free market forces; you don’t have a choice of who you take your business to, and so it’s the constitutional duty of the Corporation Commission to regulate those utilities and to guide them in a way that is beneficial for all of Arizona.”

Polacheck took that argument a step further, claiming the current Republican-controlled commission’s policies unfairly incentivize the use of fossil fuels.

The Democrats claimed a utility mix that includes more solar would save Arizonans money.

“We could benefit from, you know, producing energy just in our backyards and with solar over time costs would go down,” Aguilar said.

With three of the commission’s five up for election, the results in November will determine which party controls the agency that regulates many of Arizona’s utilities over the next four years.

Republicans currently control four of the commission’s five seats but Republican Commission Chair Jim O’Connor and Democratic Commissioner Anna Tovar are not seeking reelection.

Whoever wins in November will serve alongside Republicans Kevin Thompson and Nick Myers, who are not up for reelection this year.

In addition to the Democrats and Republicans in the race, Green Party candidates Mike Cease and Nina Luxenberg are also seeking seats on the Arizona Corporation Commission. They did not qualify for the debate under rules adopted by the Clean Elections Commission and the Arizona Media Association.

KJZZ reporter Greg Hahne contributed to this report.