June 12 - State law in Hawaii, USA mandates that by 2030, at least 70 percent of its power needs to come from renewable resources. With this policy in place, wind energy is figuring heavily in the state's current energy policy.
The Buckner Companies of Graham, N.C. has spent the last year with its 660-tonne capacity Terex CC2800-1 NT lattice boom crawler crane erecting wind turbines on Oahu and Maui, for Madison, Wisconsin based renewable energy firm RMT Inc.
The Kawailoa Wind project consists of 30 turbines on Oahu's North Shore, generating 69 MW of clean energy, enough to supply 5-10 percent of Oahu's annual electric demand, saving 300,000 barrels of oil each year.
Maui's Kaheawa Wind II project adds 14 turbines and 21 MW of power to the existing wind farm on a ridgeline of the West Maui Mountains. In total, the Kaheawa wind farm generates 51 MW of energy, enough to power 18,700 homes annually.
The wind project is the first of its kind in the US to incorporate a detailed habitat conservation plan.
The Kaheawa project consisted of 14 turbine installations and according to Buckner's heavy lift project manager Kevin Long, the plan was to erect a turbine and move the crane under its own power to the next pad site, without disassembling the crane.
The Terex CC2800-1 NT has a track width of only 5.3 m, allowing Bucker to navigate the tight roads between the turbines without damaging the protected surrounding environment. Large 5 m x 1.4 m front/rear outrigger pads worked in conjunction with two hydraulically operated side 3 m x 2.4 m outrigger pads, to give the stability required for lifting the turbines.
"We were traveling unusually high grades of up to 17.5 degrees. With its maximum 10 degree gradeability, the Terex CC 2800-1 NT efficiently handled the steep grades," Long added.
Once the 14 turbines were secured, the crane was disassembled and transported to Oahu by local contractor American Piping & Boiler Co, Kapolei, Hawaii.
From June through to October 2012, the Terex CC 2800-1 NT was used to install 30 larger 2.3 MW turbines, which required a maximum lift capacity of 95.2 tonnes. To complete the lifts the crane was equipped with full counterweight, 102 m of main boom and a 12 m fixed jib offering up to 10 degrees offset.
Because of the challenging site conditions the crane had to assembled and disassemble the crane three times. Buckner did not need to equip the crane with its optional superlift for the project. Long noted this significantly improved crane assembly and disassembly efficiency: "The total disassembly and reassembly process took two to three days. If we would have needed the (superlift) derrick, this would have added another full day to the process."
To ensure the turbines continue work at maximum efficiency, Buckner will keep the Terex CC 2800-1 NT on Oahu for five years. The company has created a joint venture with APB, American Piping & Buckner, to assist with maintenance and service of the turbines.