Project Details

Waianae Solar Energy Farm | Oahu, HI

  • Waianae Solar Energy Farm
  • Waianae Solar Energy Farm
  • Waianae Solar Energy Farm
  • Waianae Solar Energy Farm
  • Waianae Solar Energy Farm


Many projects lie well within GBI’s everyday expertise and capabilities, such as mass grading, utility installation, and concrete paving. But we also like to venture out of our comfort zone to embrace the challenges that come with new and exciting types of construction. The Waianae Solar Farm, located on Oahu, qualified as that type of project.


Our main scope of work for this project involved the installation of 12,716 driven “end” piles and 6,820 drilled/set/concrete cast-in-place motor, combiner, and center posts. For us, these required new means and methods for the piles and posts, especially because the site conditions consisted of coral, sand, alluvial soil, and thousands of surface and buried boulders. These conditions had the potential to make pile and post installation extremely difficult and time consuming.

The main challenge was drilling thousands of holes through coral and various sizes of buried boulders. On top of that, the hundreds of the center posts needed bracing to meet strict tolerances at 5 degrees from plumb on sloping grades. These design criteria were unique to the Waianae Solar Farm project, so all means and methods specific to these posts had to be developed from scratch. After researching various types of forms and braces that were cost prohibitive, good old human ingenuity finally won the day. GBI created a quick and effective way to set the posts using basic wood studs.


GBI won the 2017 Build Hawaii Award for Specialty Construction on the Waianae Solar project. Today the 127,160 solar panels generate 27.6 megawatts of electricity, and is the largest photovoltaic facility in Hawaii. It provides significant amounts of electricity to Oahu customers in a safe, clean, environmentally friendly, and sustainable way, while substantially contributing to the State’s efforts towards 100% renewable power generation by 2045.

Project Details

Region: Oahu
Client: REC Solar
Market: Renewable Energy
Sub-Market: Solar Farm
Value: $15 million
Completed: 2016
Services: Aggregate Crushing Mass Earthwork / Excavation


General Contractors Association of Hawaii
Build Hawaii, Award of Excellence 2017
Specialty Construction, More than $10 million

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