Randall Iwase, chairman of the state Public Utilities Commission, is resigning effective Dec. 28, according to Gov. David Ige’s office.

Ige said he accepted Iwase’s letter of resignation, dated Nov. 9, in which he wrote that he wants to spend more time with his family.

“Randy Iwase has played a key role at the Public Utilities Commission during a time of transition,” Ige said in a news release. “I thank him for his unwavering commitment to the state’s energy efficiency goals and to Hawaii’s 100 percent renewable energy future.”

The PUC regulates all chartered, franchised, certificated and registered public utility companies operating in Hawaii.

Ige announced the appointment of Iwase as chairman of the PUC in January 2015. Iwase presided over the PUC in 2016 when the commission voted to reject Florida company NextEra Energy Inc.’s proposed $4.3 billion purchase of Hawaiian Electric Industries Inc.

Ige will appoint a replacement for Iwase, whose term expires June 30, 2020, subject to state Senate confirmation.

Iwase, who turns 71 on Dec. 1, is a former state senator and was the Democratic nominee for governor in 2006 when Republican Gov. Linda Lingle won re-election.