Sea2shore cable to be shut down

In March, so work can be done on mainland substation
Sat, 02/03/2018 - 7:15am
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The Block Island Power Company will be reverting to diesel generation, temporarily, to power Block Island. That will be due to National Grid shutting down its sea2shore transmission cable for about a 20- to 24-hour period in March to conduct work on its substation in Wakefield.

National Grid’s cable shutdown is scheduled for March 13, said BIPCo President Jeffery Wright, who noted that the date and time could change. The 30-megawatt capacity sea2shore cable connects Block Island to the mainland and is the transmission system for the Block Island Wind Farm. A substation is the equipment that transforms the high voltage of electrical power transmission to a lower, suitable voltage for consumers, and vice versa.

Wright told The Block Island Times that, “National Grid has asked BIPCo, and Deepwater Wind, to coordinate an outage to the sea2shore cable, so that they can facilitate work at their Wakefield substation. National Grid needs 20 to 24 hours to do their work. This is a routine request, and one that I expect we’ll probably get from time to time, which is one reason we (BIPCo) are maintaining our fleet of (diesel) generators.”

Michael Masseur, a spokesman for National Grid, said the company has “some foundation work to perform at the Wakefield substation that requires de-energization for safety reasons.”

Deepwater Wind spokesperson Meaghan Wims said the developer “and National Grid are in close communication regarding all maintenance activities that could impact Block Island Wind Farm operations. Based on standard operating procedures and safe electrical work practices, when National Grid conducts maintenance on the sea2shore cable, the wind farm will be offline for the duration of the cable maintenance. For the currently scheduled March 13 National Grid planned maintenance event, we anticipate that the Block Island Wind Farm will be offline for less than half of a day.”

Wright said, “BIPCo will run one of its back-up generators to power the Island during the time that the cable is out of service.” He noted that BIPCo currently has four diesel generators at its disposal. “One generator is brand new, and three are older units that are well maintained.”

“We are always ready for the cable to go out, so beyond proactively notifying our customers of the plan we are ready to provide internally generated power when the cable is out,” added Wright. “We are also doing everything between now and then so that we can support the outage without taking a momentary interruption to cut over.”

As for what the switch to diesel will mean to the Island’s ratepayers, Wright said it should equate to less than 50 cents being added to that month’s power bill. “We need to verify what our fuel adjustment charge is right now, but it will be in the neighborhood of 16 to 17 cents per kilowatt-hour. At this point we are planning to implement that fuel adjustment charge in lieu of the transmission and standard offer charges for the hours that we run the generators.”

“Our combined standard offer and transmission charges are 14.88 cents right now, so the increase in kilowatt-hour charge will be roughly two cents per kilowatt-hour,” said Wright. “An average customer who uses 500 kilowatt-hours per month will see an increase of less than 50 cents in their month end bill.”

Wright said that since BIPCo has about 20,000 gallons in storage, the company, which prior to cable installation purchased one million gallons of diesel fuel annually, will now need to purchase under 1,000 gallons annually for backup storage.