Mayor Kirk Caldwell’s administration will seek new proposals for a project to convert nearly 52,000 streetlights to light-emitting diode technology, administration officials said Tuesday.

Robert Kroning, city director of design and construction, said the do-over is necessary because negotiations with a contractor ran into a snag — not because of criticism by City Council members, astronomers and environmentalists that the criteria for the original request for proposals were too narrow and would have used an outdated type of LED lamp.

Nonetheless, Kroning said, the new Request for Proposals language should address two of the major concerns raised by critics: that LEDs with a lower “color temperature” should have been allowed and that vendors should have been required to provide control panels enabling the city to dim the lights.

“Now that we’ve had to re-solicit anyway, of course we’re going to review the technical specifications of the light fixtures and the product that we’re putting out,” Kroning said, noting that it has been nearly a year since the original RFP was prepared. “As you can imagine, LED technology is growing by the month.”

In response to concerns raised by scientists and environmentalists about the RFP, Council members in September adopted a resolution demanding that the administration give a status report.

Caldwell first proposed the LED conversion in his February 2014 State of the City speech, when he described the new lights as brighter, cooler and cheaper.

Kroning, appearing before a Council committee in August, said Ameresco Inc. had been awarded the contract for the retrofit. At the time, the city was finalizing a contract with the company and expected to see the first lamps installed by the end of the year.

On Wednesday, however, Kroning said the award to Ameresco had been rescinded recently because the city learned, just as the contract was to be signed, that the company was seeking “additional documents for its tax exemption.” The city could not accept that condition, and efforts to resolve the situation were unsuccessful, he said.

“In the end we realized that we couldn’t go through with the change in the financing request by Ameresco because it wouldn’t have been fair to the other offerors who didn’t submit their offers with the same conditions,” he said.

Because the city is restarting the proposal proc-ess, the project will be pushed back a year, and the first of the LED lights likely won’t be installed until the end of 2016, Kroning said.

Officials previously estimated it would take about four years to replace roughly 51,700 streetlights islandwide.

The city is not losing any money due to the delay, but the lights in the original proposal would have used less electricity, for an anticipated cost savings of about $3 million annually, Kronig said. The administration has always envisioned the project as one where the vendor was to foot all the initial installation costs, he added.

The new RFP, expected to be out by May 1, will include language that will allow for consideration of financial options such as the one sought by Ameresco, he said.

A major criticism by those objecting to the original RFP involved language that said specifically that the LEDs emit a rich blue light. The critics said such light would create a blue glow around the island that would be unhealthy for people and animals; reduce visibility of the stars not just on Oahu, but at the observatories at Haleakala and Mauna Kea; and create an unpleasant atmosphere that would make it difficult for people to sleep. They argued that the specifications should require lower “color temperature.”

The critics also complained that the RFP should have required potential vendors to provide control panels that would allow for the dimming of lights to meet the needs of individual neighborhoods.

Kroning called the criticisms “minor” and said he was OK with the technical specifications in the original RFP. “It’s been almost a year since we prepared the RPF initially, and … there have been changes, updates, advances in LED technology that of course we’re going to look into, and adjust some of the technical specifications to accommodate that,” he said.

However, he added, “Nothing is definite.”

Kroning said the city will continue to ask vendors to “bring in product that is better than what the basic specifications asked for.”