National Grid returning to finish cable reburial

Thu, 09/09/2021 - 2:30pm
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National Grid is gearing up to return to the island in October to continue the reburial of its sea2shore cable. This is the undersea electric transmission cable that connects Block Island to the mainland. Installed in 2016, both the sea2shore cable and the cable connecting the island to Orsted’s Block Island Wind Farm were exposed by waves and shifting sands several years ago. The cables were buried on the island side using a jet plow, while on the mainland side the cable was buried using a horizontal directional drill.
The jet plow, while less expensive, was not as effective as the horizontal drill in deeply burying the cable. In fact, the cable on the Block Island side was only buried to a depth of four feet in places, but was still approved by the Coastal Resource Management Council.
Beginning in October 2020, National Grid and Orsted worked together using a horizontal directional drill to make tunnels from just north of the Beach Pavilion, under the dunes, under the sea floor, and out to an underwater pit off the shore. At places, this tunnel is 30 to 40 feet under the ocean floor.
Crews built 3500-foot conduit pipes to snake through the tunnels, from the ocean back to the shore. Once the conduits were in place, Orsted ran a new length of cable through its conduit pipe and spliced it into the rest of the line.
National Grid encountered problems, however, when running its cable through its pipe. National Grid reported “unexpected material causing partial obstructions” within the conduit. After working unsuccessfully to clear the obstructions, National Grid pulled the plug on the operation for the summer season.

“This was an extremely difficult decision, but we recognize the importance of the summer tourism season for the Block Island community,” said Terry Sobolewski, President of National Grid Rhode Island, back in May. “We need to assess what is causing these obstructions, how best to get the pipe cleared, and ultimately complete the installation with confidence in the fall. We’re disappointed we won’t be able to get the cable completed by Memorial Day as we planned, but this is a very complex construction project. We’d rather get it right in the fall than try to rush completion of it now.”
It was reported by Reuters that National Grid will be partnering with German utility RWE to develop more offshore wind projects in the U.S.

National Grid is also collaborating with Orsted and EverSource, New England’s largest energy delivery company, serving customers in Connecticut, Massachusetts, and New Hampshire. The partnership is developing a 704 megawatt project, Revolution Wind, which will provide 304 MW to Connecticut and 400 MW to Rhode Island. This project will begin construction in 2023 and will be located 15 miles south of Rhode Island and 12 miles southwest of Martha’s Vineyard. For comparison, Orsted’s Block Island Wind Farm is a 30 megawatt operation. National Grid will be working with the Revolution Wind project to bring the energy to the mainland.

On Block Island, Town Manager Maryanne Crawford reported the following to the Town Council on August 18: “National Grid will return to the island in early October. They have pressure tested the high-density polyethylene (HDPE) conduit; it showed a slight dip in pressure but not enough to raise concern. The following steps by National Grid include camera investigations of the conduit. Based upon the latest discussion with National Grid, the camera investigation is slated for early October. The result of that investigation will determine the next steps.”

It is unclear how these delays and problems will affect the $31 million cost of the reburial project.

In April, the Providence Journal reported that National Grid had generated a $46 million profit from surcharges to ratepayers for maintenance and upkeep of the sea2shore cable.

National Grid told The Times “the assertion that National Grid has made $46 million in “excess profits” from the BITS Surcharge is simply untrue. In a year where the BITS revenues exceed costs associated with the cable, the excess revenues are used to absorb the costs of running National Grid’s Rhode Island business.”

State Representative Anastasia P. Williams, of Providence, called it a “scam of the highest order,” as National Grid did not use the money for the reburial project, instead capitalizing the $31 million cost of reburial into the total cost of the overall project, which now stands at $145 million.