Situation
Set on 300 acres in Hawai‘i Island’s South Kohala District, Waikoloa Solar Farm is the island’s first utility-scale solar farm. It has a 30 MW solar photovoltaic array and 120 MWh containerized lithium-ion battery storage system. Under a 25-year power purchase agreement, the solar farm is slated to deliver power at $0.08/kWh, one of the lowest rates in the state for renewable energy and far less than the cost of fossil fuel power. It is expected to contribute approximately 7.1 percent of Hawai‘i Island’s energy needs and result in a total avoided fuel consumption of 511,086 barrels of oil over its quarter-century lifespan. At the end of the 25-year period, the solar farm will be decommissioned, and the area will be returned to its existing condition.
Solution
GBI’s scope of work included early budgeting, design review for constructibility, and design optimization for the development well in advance of the award by HELCO to AES. Once actual construction started GBI’s scope included: mass grading of more than three miles of roads, along with the solar farm’s substation and switchyard pads. GBI also processed rocks for aggregate, installed drain lines and drainage swales, and formed and poured the PCS (power conversion station) pads. Additionally, GBI placed the road aggregate and excavated and backfilled for electrical. The GBI project team helped the general contractor fine-tune the initial scope of work to make it more cost- and time-efficient. The team also had to contend with uneven, ultra-rocky terrain, as well as dusty volcanic ash that was difficult to control with water. GBI paused its work several times to assist local fire crews battling wildfires nearby and provided D9 and D10 dozers to help with the firefighting efforts. Despite the disruptions, the project remained on schedule.
