Costco’s solar project, like most of its products, is big

Construction of carport-style support structures has started for solar panels in Costco Wholesale’s parking lot in Kahului. The project aims to generate 670 kilowatts of electricity daily, providing the warehouse store with about 18 percent of its annual energy demand. -- The Maui News / MATTHEW THAYER photo

Costco Wholesale has begun construction of carport-style support structures for the eventual installation of solar panels in the store’s Kahului parking lot off of Haleakala Highway.

Work on topping off the structures with photovoltaic panels is not expected to begin until mid-January.

The project’s estimated cost adds up to nearly $5 million, according to a dozen building permits issued by Maui County in December 2016. The general contractor is listed as Jovencio G. Corpuz.

The photovoltaic system is designed to generate 670 kilowatts daily, providing for about 18 percent of the store’s annual energy needs, said Craig Peal, an assistant vice president in Costco’s Energy Department during a presentation to the Maui Planning Commission in March 2015.

At the time, Costco had 84 solar installations at its stores in the United States and Puerto Rico, he said. Nearly all of the Hawaii Costco stores were outfitted with solar power.

To be completed, the solar panel support structures need concrete columns and crossbeams. The solar panels are not scheduled for installation until mid-January. -- The Maui News / MATTHEW THAYER photo

Installation of solar power at the Kahului warehouse was slowed because the roof of the building, originally constructed in 1996 and remodeled in 2012, was unable to support the weight of solar panels, said architect Brian Dobry of MulvannyG2 Architecture.

“In order for the roof to support such a system, significant and costly structural upgrades would be required which would negatively impact the store operations,” Dobry told planning commission members.

Peal provided more detail about the difficulty of retrofitting the building to support a photovoltaic system. The warehouse rooftop could only handle a 600-kilowatt system, he said.

“There’s a lot of skylights,” he told commission members. “There’s a lot of air-conditioning equipment. We have to maintain access to everything on the roof in order to maintain it properly.”

And, the building “wasn’t designed to accommodate the additional weight and wind load that we would get on solar panels on the roof,” he said. “Even if it’s feasible . . . you would have to go into the building and almost shut it down. You would have to weld additional bracing throughout the entire building. And it would probably take a month to do it. You can’t bolt it. You have to weld it on. . . . It’s incredibly disruptive to the business. It’s very expensive. And so it just didn’t seem to be an option.”

The solution was to build carport solar structures in the parking lot.

“With the system, it will not only provide sustainable energy, but it will also provide shade for the cars during the day and lighting for the customers at night,” Dobry said.

The carport structures are pitched at angles to catch as much sunshine as possible, he said. The project is not designed to provide power to Maui Electric, he added.

Peal said the project’s planning took into account its impact on utility’s power grid. “We kind of sized the system as large as we can size it without becoming a problem for the local utility,” he said.

A few years ago, Costco built a carport solar structure at a store in New Mexico, “and it worked out really well,” Peal said. Building the carport structures is less expensive than reinforcing the warehouse building to carry the solar panels would be, he said.

He called the project “simple and straightforward.”

“It’s a shade structure with solar power on top,” he said. “It supplements the utility power that we take in during the day.”

Project plans call for mounting 28,000 square feet of photovoltaic cells atop the carport structures. Some trees will be planted and relocated as part of the work at the 17.2-acre site zoned for heavy and light industrial use.

During the March 24, 2015, planning commission discussion of the project, then-commission member Wayne Hedani called the carport structure “butt ugly.” He suggested screening it with landscaping, according to minutes of the meeting.

David Sarita of Chris Hart & Partners said there would be some landscape screening. But, “the trouble with putting trees next to the structures is, obviously, dropping things on the panels and then shading the structure from the sun,” he said.

Existing monkeypod trees were relocated to avoid that.

Commissioners approved the special management area permit, calling for the galvanized steel carport structures to be painted to create a more natural, less industrial appearance.

The support structures in Costco’s parking lot still need concrete columns. Trenching needs to be completed and crossbeams need to be installed. The solar panel installation is not expected to start until Jan. 15.

* Brian Perry can be reached at bperry@mauinews.com.


Today's breaking news and more in your inbox

I'm interested in (please check all that apply)
Are you a paying subscriber to the newspaper?


Starting at $4.62/week.

Subscribe Today