Block Island wind farm, power cable run into snags

DEEPWATER WIND completed the installation of its five-turbine Block Island Wind Farm in the fall of 2016. Because of a manufacturing error, one of the turbines has been shut down until repairs can be completed. / COURTESY DEEPWATER WIND
DEEPWATER WIND completed the installation of its five-turbine Block Island Wind Farm in the fall of 2016. Because of a manufacturing error, one of the turbines has been shut down until repairs can be completed. / COURTESY DEEPWATER WIND

NEW SHOREHAM – While renewable advocates continue to celebrate the launch of the nation’s first operational offshore wind farm, its early rollout has come with some mishaps.

Deepwater Wind LLC last month officially started selling electricity from its 30-megawatt Block Island Wind Farm to National Grid PLC, the state’s largest utility. The five-turbine project has received attention and praise both locally and nationally, as it’s the nation’s first operational offshore wind farm in what’s a nascent subsector of the energy industry.

But both Deepwater Wind and National Grid are having some early issues with the project.

Indeed, one of the wind turbines has been shut down for repairs, as 26 generator magnets were damaged after a drill bit was left inside when it was manufactured. General Electric Co. made the generator in France before it was shipped to the United States.

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The damaged 6-megawatt turbine did successfully generate power in December, but has been shut down completely as repairs are expected to begin this week and take “several weeks to complete,” according to Deepwater Wind spokeswoman Meaghan Wims.

Early estimates put the repair time at 45 days, but it should not affect the operations of the remaining four turbines.

“[The] rest of the farm [will continue] to operate as it has since December,” Wims wrote in an email.

At the same time, National Grid is grappling with its own issues, as a section of its 20-mile undersea cable that brings electricity and high-speed internet to and from Block Island, and subsequently the wind farm, failed to follow permitting guidelines. The $110 million infrastructure project was done in conjunction with the Deepwater Wind offshore wind project, and the undersea cable was supposed to be buried under the seabed at a range of 4-to-6 feet deep.

The utility, however, ran into some digging issues when it approached the Block Island shoreline.

“During the installation of the [undersea] cable in a short, 80-foot area seaward of Crescent Beach, unplowable material was encountered preventing the cable from being buried to the targeted depth,” said spokesman David D. Graves. “We are currently working with the appropriate agencies on an agreed-upon solution.”

The utility, which was laying the cable on a tight deadline, nonetheless completed the project, which allowed Deepwater Wind to complete its project before year’s end as promised. But National Grid now has to retroactively ensure the cable is in compliance.

Graves wouldn’t speculate on what it might take to remediate the mishap until the company hears from the R.I. Coastal Resource Management Council, which is currently reviewing the project.

However, the Block Island Times reports the reburying process would require the cable to be “de-energized,” which could further disrupt electricity traveling from the Block Island wind farm to the mainland.

The wind farm is expected to power about 90 percent of Block Island’s electric demand and 1 percent of Rhode Island’s, and while Deepwater Wind is currently selling electricity to National Grid for mainland electricity users, Block Island users have not yet used any of the power.

Indeed, Block Island residents in September voted to pay $1.8 million to buy the controlling interest of Block Island Power Co., the island’s utility. The island is now in the process of taking over the utility, and must invest in it in order for its systems to be able to draw power from the wind farm, which is expected to happen sometime between March and April.

How the future cable work might affect future connectivity to the mainland, however, is presently unclear.

“Deepwater will review Grid’s plan for work on the [undersea] cable, but we don’t anticipate any significant impacts to the wind farm operations,” Wims wrote.

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