B.I. Wind Farm foundations installed

All five steel jackets reside in the water
Fri, 09/25/2015 - 8:00am
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All five steel foundations are now in the water, as the $290 million Block Island Wind Farm begins to take shape three miles off the southeast coast.

The 30-megawatt Deepwater Wind pilot wind farm project appears to be on schedule. Deepwater Wind representatives have said that they wanted to have all five in the water by the end of September.

The final jacket that was installed in the water was foundation number four. Foundation number one, which was removed from the ocean after initially being installed due to disrepair, is now back in the water.

“All five jackets are in the water now,” said Deepwater Wind spokesperson Meaghan Wims. “It’s a big step for the project with more work to come. Construction activities will continue with pile driving and installation of the jacket platforms in the coming weeks.”

The jacket platforms that Wims mentioned include the deck component that will be welded to the top of the foundations. The deck components, which are 56 feet tall and will be 13 feet above the waterline, are equipped with solar panels for an aid-to-navigation system and an equipment well that will be capped off.

The five 1,500-ton steel jacket foundations are being pile-driven 200 feet down into the seabed, securing the foundations to the seafloor, via a crane utilizing a hydraulic hammer. A variety of cranes — including two different models of the Weeks crane as well as cranes on the L/B Robert, have been employed on the project to handle various construction activities.

Resident Bill Curtiss, who owns a home across the street from the Southeast Lighthouse and has had a front-row seat for the installation process, said that the hydraulic hammer has “not been loud or intrusive” while conducting the pile driving process. “Of course, we hope the same holds true when the turbines are up and running,” he said. Others on the island would disagree.

“Now we know where the bases will be, and our view from the house will see at least three,” said Curtiss, 76, who noted that he witnessed relocation of the Southeast Lighthouse on Mohegan Bluffs in 1993.

Curtiss said that he has noticed that “the wind farm in the water has moved forward very well for the developers. The impact will come into view in time, and hopefully changes to the sea and landscape will fade into the background. Remember the first cell phone towers?”

The wind farm was not always going to be just five turbines.

At a January 14, 2015 public hearing at the Warwick offices of the Rhode Island Public Utilities Commission (PUC), Deepwater Wind CEO Jeff Grybowski acknowledged that an early plan for the Block Island Wind Farm included eight total wind turbines.

“When we first thought about the Block Island Wind Farm back in 2008 or 2009, we were thinking about what was then the latest technology for wind turbines. That was a 3.6 megawatt machine at that time,” said Grybowski at the hearing. “A few years ago, we realized that the 3.6 megawatt was a pretty old technology. So because of the movement of technology, because of the permitting, and community acceptance issues, we were able to go from eight installations to five (6-megawatt turbines) because the machines were getting larger.”  

Grybowski said that going from eight wind turbines to five wind turbines was a “wash” cost-wise, meaning that there were no cost savings in transitioning from eight to five turbines. The reason that there is no cost differential in reducing the wind farm from eight wind turbines to five wind turbines is that the 6-megawatt turbine is a more expensive machine.

Grybowski noted that each of the five steel jacket foundations were designed by Keystone Engineering and then fabricated by Gulf Island in Houma, Louisiana for their specific location on the ocean floor at the wind farm site. The steel jacket foundation is “designed both for weather conditions, sea conditions, soil conditions and the turbine,” he said.

Grybowski said that the wind farm is expected to generate 125,000-megawatt hours a year at the higher end of the 40-percent capacity spectrum. "In general, we have more wind in the winter than in the summer. Our worst months are July and August," he said. "Offshore wind tends to peak in the late afternoon and early evening. A wind farm is producing all months of the year, and every month will have pretty significant production."

The Block Island Wind Farm is located in the CRMC’s (Coastal Resources Management Council) renewable energy zone, an area deemed by the CRMC as suitable for an offshore wind farm project.