Anchorage-based STG Incorporated constructed the array, using the Kobelco CK1000 crawler, the latest edition to its 15-strong crane fleet. The crane was purchased new and barged to the Unalakleet jobsite on Alaska’s west coast, alongside another CK1000, after arriving in the US from Japan.
Clinton White, business development, STG, said the lifts needed to erect the Northwind 100 turbines, which are manufactured by Canada’s Northern Power Systems and include 6t nacelles, 1.8t blades and towers weighing up to a total of 14t, were straightforward. But, White said, due to the remote location of the wind farm, STG faced logistical issues.
“We were managing 27 heavy industry jobs across the state last year, and it was critical that we were able to have our heavy equipment into and out of Unalakleet during their short four month construction season.
“Organising the logistics associated with personnel, supplies and equipment are critical if a project is to keep schedules and stay on budget, and this does get pretty complex when moving equipment from small isolated locations during a relatively short construction/shipping season.”
White added: “Without tight controls in this area, we also risk losing productivity due to the remoteness of our projects and the time necessary to re-organise or attempt to re-send project materials. Organising a heavy industry project in the bush is complex and time consuming in any situation, but for Unalakleet we were not given an official notice to proceed until May 2009.
“At that point we immediately took steps to organise the work, had our equipment on site by 4 July and all construction activities completed by mid-September. In the end, this was one of the fastest installations we have completed to date,” said White.
The wind power installation has been erected to provide energy savings for the Unalakleet community, and help stabilise the cost of energy across the area. It is connected to the Unalakleet Valley Electricity Cooperative’s (UVEC) existing distribution system and diesel-powered generation facilities. UVEC is a non-profit member cooperative providing electricity services to around 750 residents and local businesses in Unalakleet.
The array is expected to deliver 1.5 million kWh of wind electricity to UVEC annually, accounting for 35% of the Unalakleet community’s energy needs. To date, it has saved around 21,000 gallons of diesel fuel for UVEC.
“Like most all-rural Alaska utilities, we have seen a dramatic increase in the delivered price of our primary fuel source, diesel, over the last five years,” said Ike Towarak, UVEC general manager.
“The wind installation will help us be better prepared to manage ongoing operational costs at the utility.”
White said the job was special because Alaskan wind farms are not typical to others across North America.
“In Alaska, wind installations are quite different from what is commonplace in the lower 48 [states] primarily due to the fact that we are connecting wind into small, isolated diesel power grids,” he said. “Wind projects are installed into these existing systems with the primary objective of reducing fuel consumption for the local utilities as much as possible.
“Nonetheless, due to the small size of these rural grids, large MW turbines are not too appropriate for our market in most applications. They are too large for rural electrical needs and would crash these systems.”
While the wind project installation has been completed, the array will run at a reduced capacity until UVEC’s new power plant is constructed later this year.
