Hawaiian Electric Co. is backing down from a proposal to freeze installations of photovoltaic systems on some islands until studies could be done on how their use is affecting the stability of electrical transmission grids.

The utility yesterday said it was asking the state Public Utilities Commission to rescind a request made earlier this month to stop the installations when homeowners and buildings are connected to its electrical grids on the Big Island, Maui, Lāna'i and Moloka'i.

It requested the moratorium pending studies that could review concerns the utility has about system reliability and stability and come up with technical and policy solutions if needed. The utility said it had seen some problems with grids tripping off-line that it believes were caused by increasing amounts of photovoltaic systems.

But HECO's proposal surprised photovoltaic system installers, some of whom said a suspension of work would drive them out of business. They said the request was unjustified at the current levels of photovoltaic systems on the islands and that they doubted HECO's claims about system instability, because no specifics had been given on the outages.

Yesterday the utility said it regreted the unnecessary and unintended alarm among PV companies.

"It was not meant as an immediate stop," said Robbie Alm, Hawaiian Electric executive vice president.

"Instead it was a signal that we need to move promptly to address these major issues to avoid tough choices."

Ted Peck, state energy administrator, said he was encouraged by HECO's position change.

"They have recognized the sensitivity of the community to this issue," said Peck, explaining that the state has been trying to foster collaboration on renewable energy issues as it drives toward a goal of getting 40 percent of electrical power from sustainable resources and another 30 percent through a variety of conservation issues.

"The fact we are among the first in the nation to really contend with this issue is one more affirmation of the groundbreaking work we're doing in this state."

Others, while applauding HECO's changed position, harbored questions about the utility's motives for requesting the action in the first place. Jeff Mikulina, executive director of the Blue Planet Foundation, noted that HECO signed an agreement with the state to help foster renewable energy use here.

"Now is the time for the utility to meet their end of the obligation," Mikulina said. "It's a new era for energy."

There, too, remains a divide between the utility and some of the installers, who see HECO as focusing on photovoltaic installations as a cause of problems, when that might not be the case.

"We've never been shown that PV installations are causing these outages," said Mark Duda, head of the Hawaii Solar Energy Association.

"I'm not saying that can't happen, but we've never been told or shown data that that had happened."

Duda also praised HECO, though, for changing its proposal. "It's nice that they've disavowed this plan."