When Hawaii Public Utilities Commission Chair Randy Iwase gaveled an end to proceedings Tuesday aimed at helping regulators decide whether NextEra Energy’s purchase of Hawaiian Electric Industries passes muster, the countdown to a decision began.

This comes nearly 15 months after the two power companies announced a $4.3 billion merger that could put Hawaii’s main power utility in the hands of the Florida-based energy behemoth.

Iwase, who has been acting as a sort of lead judge for the commission, noted that the high-stakes hearings have “gotten contentious at times, but it was always civil.”

Seconds later, he adjourned the hearing.

And after handshakes and even some hugs around the room, dozens of lawyers, intervening parties and others went their separate ways.

The immediate question, after the 22nd day of testimony by 51 witnesses and the exchange of tens of thousands of pages of competing filings, is: What’s next?

All of the intervening parties at the hearings, as well as the Consumer Advocate, are supposed to file final briefs by March 31. Hawaiian Electric is supposed to file its reply briefs by May 2 — its last formal chance to affect the decision of regulators.

Then the commission is expected to begin processing the final information, engage in deliberations and decide the fate of the merger.

“From our point of view … the evidence upon which we’re going to base our decision is in,” Iwase said Tuesday. “We base the decision on the record; there’s nothing extraneous to it.”

Asked if this means that the window for sweetening the deal has closed, he replied: “For us, it has.”

If NextEra and Hawaiian Electric want to continue trying to influence the parties in the case, he said, it is their prerogative.

“I don’t begrudge them for trying,” he added, before noting that any new settlements between parties would not bind the regulators in any way.

NextEra had been engaging in side negotiations in the weeks before the hearings opened. Those talks came to fruition with the Department of Defense, which sought to withdraw as an intervening party after NextEra sweetened its list of promises with 10 additional commitments. Talks with the Ulupono Initiative proved fruitless.

Beyond the obvious question about how the three-member commission will vote, there are more immediate questions: When will the decision be made? And, if regulators offer conditional approval, what conditions might they slap on the deal — and would that be acceptable to NextEra?

Some members of Hawaii’s business community are concerned that a regulatory rejection of the deal might aggravate perceptions that Hawaii is anti-business. They also worry it could slow progress in improving the state’s energy environment.

Rob Gould, NextEra Energy’s spokesperson, issued an optimistic statement that emphasizes the extensive regulatory hoops his company has gone through:

“After 22 days of hearings and having filed approximately 110,000 pages in response to 6,000 questions over a period of more than one year, as well as the broad-based support that we have received from so many across the state including business, labor and community groups, we remain steadfast in our belief that NextEra Energy is the right partner for Hawaiian Electric and that our merger will deliver real and tangible benefits to Hawaiian Electric customers and the state of Hawaii.”

During the final day of testimony, Henry Curtis, the executive director of the nonprofit Life of the Land, warned that a NextEra takeover of Hawaiian Electric would result in the layoff of more than 1,000 employees.

Under cross-examination, Curtis, who appeared on behalf of a trio of intervening parties, acknowledged that NextEra did not say during the proceedings that it plans to get rid of Hawaiian Electric employees, but he insisted that a careful look at the past behavior of NextEra subsidiary Florida Power & Light shows the company has often saved money by getting rid of employees.

As part of its 95 purchase-pledges, NextEra has promised a two-year moratorium on layoffs at Hawaiian Electric; something that HECO has never promised its own employees.

Attorneys and executives for NextEra and Hawaiian Electric have noted that the International Brotherhood of Electrical Workers has formally come out in support of the deal, which the union would not be likely to do if it believed large-scale job eliminations were in the offing.

“I would say that IBEW did not understand the ramifications,” Curtis testified.

While that was one of the last issues raised at Tuesday’s hearing, the broader debate over the merger is likely to continue in the public sphere — in advertising and activism — for the months to come.