When is an onshore turbine installation more like an offshore job? When the turbines are headed for an island. Consider the wind energy project going up on Fire Island, a 5.5-mi long dollop in the Cook Inlet near Anchorage. The site proved such a formidable challenge for the companies involved that they treated it almost like a military invasion. Logistics involve a staging area on the mainland, beach landing craft transported heavy equipment, a watchful eye was kept on the extreme tides, and D-Day like scheduling helped deliver one turbine a day.
The heavy lifting began several months ago when trucks and equipment were brought over to build roads and foundations. Earlier this year, turbines and towers arrived from several countries to the staging areas. The initial project calls for 11 GE, 1.6-MW turbines. Towers came in from China and the blades from Brazil. All the large components were gathered into the Port of Anchorage.
One tiny challenge however: There are no docks or port facilities on the island. So Anderson Trucking Service Inc. (atsinc.com) the company responsible for logistics and transportation of the heavy components, contracted with Alaska-based contractor Brice Inc. (briceinc.com) for its landing-craft style vessel to transport each nacelle, tower, and blade.
“We planned the transport part of the project in a roll-on roll-off basis,” says Joe Goering, vice president of ATSI. Planning also called for special heavy-haul trailers, loaded with blades or tower sections or a nacelle. These were backed onto the landing craft in Anchorage. This means similar beaches were prepared at the Port of Alaska and on Fire Island. “The landing craft is actually an articulated tug and barge or ATB,” says Alba Brice, General Manager of Brice Marine LLC. “The arrangement hydraulically connects a tug to the barge through a ram that come out of either side of the tug’s hull into notches in the barge. And instead of pulling a barge, the tug pushes the craft.
The loaded barge is then pushed across the inlet up onto a stony beach at North Point on the island. And the angle on those beaches was critical because the trailers are so low to the ground. “If the ramp is too steep, efficiency for loading and unloading cargo may be impacted and project delays could then occur,” adds Brice.
When loaded craft arrived at the island and the receding tide let the landing craft sit on solid beach, the ramp would drop, several tractors would back onto the barge, hook to a trailer, and take it to a prepared pad site. A crane at each site unloaded the trailers.
To keep the project on schedule, the Brice and Goering were reminded that the Cook inlet has the second most extreme tidal swings in the world, almost 30 ft twice a day, a change just shy of Nova Scotia’s Bay of Fundy which swing over 30 ft twice a day. Another challenge with the Cook inlet: icing and ice flows start in November and last to mid-April, when its ice free again. So nothing goes onto or off the island by ship in that period.
“At the project’s end, we’ll dismantle the cranes, put them on trailers, and move them back to Anchorage for work somewhere else,” says Goering.
The turbines now stand almost in a line at the south central part of the island. Completion and commissioning is scheduled for the end of September. Power will transmit back to the mainland through a 34.5 kV submarine cable.
Although Goering makes the logistics sound easy, he says the project has produced the highest anxiety work his company has ever done. “A lot of things had to go in our favor to complete successfully and on time.”
So what makes this project so different? “First of all, these components are so large and heavy they produce a lot of center-of-gravity issues, challenges that could tip a landing craft or trailer. So we had to learn to load the landing craft. We had to calculate the water depth needed for the vessels to pull off after unloading. We were constantly second guessing ourselves. For instance, was there too much angle on the ramp based on the tides? Will the trailers get caught on something because there is so little clearance? These are low-profile trailers, so most concern was because of the dirt and gravel births in Anchorage and Fire Island had to maintain a proper angle. This was necessary so that when the tide goes out, the barge sat exactly so and the ramp gave us a straight drive off. There are a few things we had not done before so it was necessary to define them in detail before we put them into practice. As for the unknowns, we kept asking ourselves: Did we ask all the right questions? So far it has been working well,” he says.
“We learned a lot,” says Goering. “In addition to loading a landing craft, transporting heavy objects to remote locations. It’s one more tool for us,” he says. “The size of these structures and the state of the roads now lets us provide proven practice for moving large components to islands that have no conventional infrastructure, in part thanks to the beach landing craft. The landing craft, that articulate tug and barge, provides a viable option for isolated islands no matter where they are.” WPE
Alaska is so big. Why Fire Island?
Because it’s the best potential site based on wind resource, proximity to Alaska’s Railbelt electricity grid load centers, minimal environmental impacts, and a lack of conflicting land use – its uninhabited, according to Cook Inlet Region Inc. (CIRI) owner of the wind farm. CIRI owns 3,600 acres on the island and the wind farm will be Southcentral Alaska’s first large-scale wind project.
“Our goal is to help diversify the region’s power resources. Southcentral Alaska residents are more than 90% dependent on locally produced natural gas to generate electricity,” says Jim Jager, spokesman for CIRI. “The other 10% comes from local hydro. Adding wind energy to the mix is an important step away from our region’s overdependence on natural gas and toward resource diversification that provides greater energy security and price stability.”
The price of natural gas in Anchorage is rising because Southcentral Alaska cannot import gas from outside of the region, but producers can export liquefied natural gas (LNG) from the region to Asian markets, especially Japan where demand is increasing.
“Fire Island Wind energy is not tied to fuel prices. Its price is fixed by a 25-year contract that will not be impacted by the gyrations of world oil and gas markets.” adds Jager.
What’s more, the wind farm will generate most of its power during the winter months when Alaska is cold and dark, and local residents use the most electricity. Grant funding from the Reinvestment and Recovery Act provided financing to substantially reduced the cost of wind power to utility customers.