PHOENIX – Arizona’s largest electricity supplier announced Wednesday that it was committed to supplying customers entirely with clean energy by 2050.

Arizona Public Service planned to fuel the carbon-free process in phases, starting with a target of 65% clean energy by 2030 and ending all reliance on coal by 2031.

“We see incredible things ahead for Arizona, and are excited to power our state’s future with electricity that is 100 percent clean,” Chairman and CEO Jeff Guldner said in a statement.

The company said the transition would be “sensible.”

“Our clean energy plan will be guided by sound science, and will encourage market-based solutions to climate issues,” Guldner said.

Nearly a year ago, the public utility unveiled a clean-energy initiative that would allow unused solar energy to be stored then accessed after dark. That would add 950 megawatts by 2025.

Palo Verde nuclear plant west of Phoenix generates about 25% of APS’ power. Other energy sources include coal at 22%, gas and oil at 26% and renewables at 16%.

A coal-fired generator the company operates in northern Arizona will be shut down by the end of the year, it was previously announced. Two more will follow in five years.

“We do not take that transition lightly, and are committed to working with our employees and stakeholders on the economic and other effects of retiring those assets,” the statement read.

APS serves about 2.7 million people in the state.

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