Public Utilities Commission Chairman Randy Iwase has the unenviable task of deciding which documents should remain confidential as part of the proposed $4.3 billion NextEra Energy Inc. buyout of Hawaiian Electric Industries Inc. But as hearings on the proposed purchase enter into its second week today, we urge Iwase to err on the side of transparency.

It’s crucial that the public have access to all relevant information tied to a proposed sale that will certainly alter the energy landscape of Hawaii. Already, the future for ratepayers is riddled with unknowns — and they deserve answers.

However, much of the information provided by NextEra in arguing for approval of the sale has been marked confidential. And at this critical stage, it’s unclear how much of that information will remain secret, never to be discussed in public.

The hearings, which began a week ago and run through Dec. 16, have largely remained an open process, although on Tuesday the hearing ended in a 45-minute closed-door session while the state Consumer Advocate and Hawaii Gas Co. cross-examined Hawaiian Electric Co. CEO Alan Oshima about emails between HEI executives about the NextEra deal.

Then on Thursday, one participant questioned how much money NextEra expects to save by reducing operating costs. That important figure is on a document marked confidential — among the thousands of pages deemed confidential by NextEra — thus couldn’t be discussed openly.

Iwase has gotten at least three more requests from participants to temporarily close hearings again, which inevitably undermines the purpose of having “public” hearings. The PUC chairman has stated he doesn’t like having to meet behind closed doors, but says his hands are tied.

Still, in a potentially positive step, participants were asked to submit by last Friday their lists of questions they want to ask pertaining to confidential documents, and Iwase wants them to explain why the documents should remain confidential and why they are relevant to the PUC decision. Iwase can make the documents public if he decides there is no valid reason to keep them secret.

Already, the state Office of Planning had requested that the Hawaiian Electric emails be made public, but Iwase’s decision to keep them under wraps stemmed from a prior agreement made between parties. Whether those emails shed light on the proposed buyout or offer insight into the utility’s future plans is unknown, which is unfortunate for Hawaii ratepayers, who surely have a vested interest. Let’s hope that specific decision doesn’t set precedence for the remainder of the hearings.

It’s understandable that some of the information will need to be kept confidential. NextEra is not being pressed to give up its trade secrets — but in proposing to buy the state’s largest utility, there is reasonable expectation that information about cost savings, rates and plans for reaching 100 percent renewable would be available for public consumption.

Through the public hearings, we’ve learned that the $60 million in cost savings for customers would amount to $1 in savings per month over four years. Beyond those four years, it’s anyone’s guess. Under questioning Wednesday, NextEra Energy Hawaii President and CEO Eric Gleason said that all costs related to Hawaii’s goal of getting to 100 percent renewable by 2045 would come from ratepayers except projects done by individuals. NextEra has stated moving to 100 percent renewable would cost an estimated $30 billion.

Gleason repeatedly refused to answer questions about the 85 commitments NextEra offered in its proposal to purchase HEI, saying the answer to all those questions is “I don’t know.” When asked about NextEra’s specific plans to get to 100 percent renewable energy goals, Gleason said they have yet to be determined.

Hawaii ratepayers deserve better than “to be determined” and “I don’t know.”

NextEra has had a year to come up with answers, or even best guesses, to many of these questions. Being evasive at this point will not win the favor of ratepayers, nor should it impress the PUC.

If NextEra isn’t providing answers under questioning, perhaps those answers exist in documents marked confidential — and should be unmarked as such in the public’s interest.