PHOENIX — Arizonans will get to decide whether they want to require utilities to produce more of their power from renewable sources.

The Arizona Supreme Court late Wednesday rejected various claims by attorneys for Arizona Public Service that the initiative sponsored by California billionaire Tom Steyer lacks sufficient valid signatures to go to voters in November.

The justices provided no details about their reasoning, promising an explanation later.

The decision drew criticism from Matthew Benson, spokesman for Arizonans for Affordable Electricity, the anti-initiative group that has been financed with more than $11 million from Pinnacle West Capital Corp., the parent company of APS.

But with the Supreme Court having the last word, Benson said the group now will focus on trying to convince voters that approval of the measure, Proposition 127, will increase their electric bills, a contention disputed by initiative organizers.

Most Arizona utilities already are under orders from the Arizona Corporation Commission to produce 15 percent of their energy from renewable sources by 2025.

This measure would boost that mandate to 50 percent, with a requirement to get there by 2030. And it would put that requirement into the Arizona Constitution.

Proponents of what is known as the Clean Energy for a Healthy Arizona initiative say they want to reduce the state’s dependence on fossil fuels, which pump pollutants into the air. There also is a separate concern about the carbon dioxide produced, which has been linked to climate change.

One of the arguments made by APS attorneys was that the initiative would mislead voters with its claim of promoting “clean” energy.

APS takes the position that nuclear power, which has no smokestack emissions, also is clean energy. But the initiative would not count nuclear power toward that 50 percent goal, something the utility’s lawyers argued is not made clear in the description of the initiative.

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The Supreme Court upheld a ruling two days earlier by Maricopa County Superior Court Judge Daniel Kiley, who said it is not up to judges to decide what is “clean” energy. Kiley rejected the contention that anyone was fooled.

Benson, in reacting to the ruling, said the initiative is not about clean energy.

“Everyone supports clean energy,” he said. “The question is whether Arizona voters are willing to double their electric bills in order to approve Prop. 127.”

APS and its supporters have produced studies to back their claim of higher electric rates. But initiative backers and their allies responded with their own reports insisting that increased use of solar power, abundant in Arizona, would result in smaller bills.