Project Spotlight: Mililani Solar II Project

Mililani Solar project

With the State of Hawaii’s goal to be producing 100 percent clean, renewable energy for electricity by 2045, the Mililani Solar project is one of the first steps of Hawaiian Electric Companies’ Power Supply Improvement Plan. Mililani Solar is a 14.7-megawatt project that will use more than 150,000 solar panels. It is currently part of the largest solar project in the state and will help contribute enough power for more than 14,300 O‘ahu homes per year. It will help lead to an estimated elimination of 106,000 tons of carbon dioxide emissions and 223,000 barrels of imported barrels of oil annually. The site is located on approximately 12 acres of former pineapple land owned by Mililani Agricultural Park.

GBI exemplified its motto, “to be the contractor of choice,” by completing the project on time and under budget while engaging in constant communication, fostering a team-building atmosphere, and keeping the owner’s expectations in mind while providing a quality project.

GBI’s work on the Mililani Solar project included clearing and grubbing roughly 12.1 acres of land, moving 11,600 CY of material, building four miles of rock driveways, digging 1.5 miles of swale, and building two substation pads.

Meeting the challenges of a difficult job:

The main challenges of the project had to do with its location, topographical survey, and specialty aggregate. Located well outside the city limits, material procurement and mobilizations needed to be coordinated well in advance. Minimizing and mitigating our impact on the surrounding community was our number one priority. Building four miles of rock driveways required a lot of aggregate and trucking it to the site and would have created large disruptions to the surrounding roadways.

With experience on previous solar jobs that had large survey inconsistencies, GBI worked with the client to do an initial ground topographical survey as soon as the site was cleared. Doing this resurvey allowed GBI to value engineer the mass grading in order to save the client time and money.

A specialty aggregate that was required for this project was initially unavailable at the local quarries. GBI worked with the design engineer, client, and the quarry to create a win-win outcome for all involved. We were able to work with the quarry and the engineer to get a gradation that met the specifications and still allowed the quarry to produce the aggregate cost-effectively. GBI worked with the quarry and the client to bring the cost of the aggregate down below the initial bid price. By working together with all the parties involved, GBI achieved a positive outcome.

Excellence in project management:

GBI’s technical expertise and familiarity with the area aided our construction team in its preplanning analysis to determine the type of challenges that lay ahead. Given the issues on past jobs with shoddy aerial topography, once GBI had access to the site, we performed a boots-on-the-ground topographical survey of the site. Doing this enabled GBI to provide a significant value-engineered savings to the client by reducing the total quantity of earthwork for the project. Our familiarity with the site also allowed us to work with the client to improve existing access conditions for their equipment prior to any work starting, saving both of us time and money. Doing this minimized any downtime and kept productivity at the highest level.

Contractor’s innovation in construction techniques or materials/value engineering:

The project design called for an expensive loosely graded rock for its service driveways. GBI proposed using base course, a better and more cost-effective aggregate. However, the design engineer preferred a larger-sized aggregate base course that none of the local quarries readily produced. GBI worked with the quarry, the client, and the design engineer to produce a special larger diameter base course that was still cost-effective for the quarry to produce, was cheaper than the original design aggregate for the client, and still met the engineer’s design requirements. The result was a 2.5-inch base course that provided the client with a high-quality finish product at a discounted price.

Contractor’s state-of-the-art advancement:

For this project, GBI used drone mapping technology to perform aerial topographic surveys of the site and get up-to-date progress of work. During the initial setup surveyed, control points were laid out around the site and an initial flyover of the work area was done with a drone after the clearing and grubbing was complete. This gave us a baseline starting point for our topographic surveys. A repeatable flight plan for the drone was developed with a preset flight altitude and path. An aerial survey was conducted at the end of every workday; the information was used to document and track our daily progress. By continuing to develop this technology, GBI will be able to better track our production and costs associated with the work we do. The result of this advancement will be GBI producing a better product for our clients at a reduced cost.

Contractor’s sensitivity to environment and surroundings:

The Mililani Solar project site sits on former pineapple land within the Mililani Agricultural Park, which is located in the heart of O‘ahu. Given the surrounding community, it was vitally important for GBI to maintain a near-invisible presence while working in the area. To accomplish this, equipment mobilization was coordinated during off-peak hours to avoid impacting traffic. When it was impossible to accommodate the delivery of materials during off-peak hours, traffic control officers were stationed at the entrance of the site to direct cars in and out, thereby mitigating any additional traffic impacts to the surrounding community.

Excellence in client service:

GBI is committed to delivering a quality project on schedule while developing a genuine and meaningful relationship with its clients. All concerns, suggestions, and advice are taken very seriously and dealt with promptly. GBI worked with the client on all aspects of this project, informing them every step of the way on schedule, cost, and all other issues. Any discrepancies or conflicts that were discovered by us were addressed with minimal cost solutions.

GBI also went above and beyond to keep the client’s best interest, schedule, and budget in mind. Given problems on previous jobs with the accuracy of the topographical survey, GBI took it upon itself to resurvey the site once it was cleared. This gave the client a more accurate and up-to-date topographical survey. By doing this, GBI was able to help the client value engineer their civil design by reducing the overall mass excavation quantities of the project, reducing the client’s cost by more than 12%, and reducing weeks off of their civil work schedule.

Contractor’s contribution to the community:

Given the project’s proximity to O‘ahu’s famous North Shore and its location overlooking the beautiful Waimea Bay and Valley, GBI took every measure possible to minimize any disruptions. Traffic control officers were stationed at the entrance of the project to help direct traffic in and out of the site in order to minimize impacts on the North Shore community.

GBI also had the unique opportunity through its partnership with the University of Hawai‘i at Manoa S.T.E.M. program to host high school interns during the construction of our three solar projects. The students were able to see firsthand the different trades, crafts, vendors, clients, and careers that are available to them in the construction industry. The interns were able to get hands-on experience by completing the day-to-day tasks that a project engineer may be required to do in his or her job. The students also got a chance to tour the site and see the different phases of construction and what it’s like to work the field.


Between March 2018 and November 2018, GBI employees worked nearly 12,000 man-hours and experienced zero (0) Lost Time Accidents and zero (0) Recordable Accidents. In addition, when the client started a weekly safety award program, a GBI employee won the award each week—a total of eight weeks in a row—until we finished our work on the project.

Safety and health are the highest values for GBI and are taken extremely seriously. It is the expectation that all personnel in the company will promptly and diligently prevent, detect, and correct hazardous conditions and behaviors. All personnel are expected to provide and maintain a safe workplace, free from recognized and predictable hazards in order to protect all workers and the general public.

In order to achieve this, a proactive approach to safety was taken. Zonar technology was used on all GBI-owned equipment to ensure daily inspections were made and logged to help identify any potential issues. A detailed site-specific safety plan was created, submitted, and approved. Activity Hazard Analyses (AHAs) were developed by office and field management for every work activity as a tool to detect and mitigate potential hazards. The AHAs were reviewed with crew members prior to performing the work and reviewed periodically as needed. Additionally, daily “toolbox meetings” were held to discuss that day’s activities with a special focus on potential hazards and how to mitigate them. Weekly mass safety meetings were held with all personnel on site to discuss safety topics, address any concerns, and review near-misses and lessons learned from other projects. Weekly foremen’s meetings were also held to discuss safety issues, concerns, and solutions.

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