In Hawaii’s high-stakes and evolving energy world, every wonky move is closely watched — and analyzed.

So the announced retirement of Randall Iwase as chairman of the state Public Utilities Commission, effective Dec. 28 and 18 months before his term expires, sets up speculation about his successor and the regulatory agency’s direction. The PUC covers a wide range of regulated industries, from transportation to telecommunications — but in recent years, it’s been the energy utilities and issues that have riveted public attention.

Iwase, appointed by Gov. David Ige in January 2015, says he’s leaving to spend more time with his family. As chairman, he was instrumental in the PUC’s 2016 rejection of the proposed $4.3 billion purchase of Hawaiian Electric Industries Inc. by Florida-based NextEra Energy Inc. The drama of that two-vote rejection — by Iwase and Lorraine Akiba — was intense since the PUC’s third member, interim commissioner Thomas Gorak, had recused himself under political pressure.

That episode highlighted just how powerful the PUC can be — and how consequential each appointee is on the three-member panel. Just re-elected, Ige now will nominate a replacement for Iwase, subject to state Senate confirmation, to join current commissioners James Griffin and Jennifer Potter.

With more “green” proposals expected, ranging from solar systems to wind farms to emerging innovations, this PUC trio and their staff will need to make wise decisions as Hawaii charges toward its goal of 100 percent renewable energy by 2045.