PROVINCETOWN — The first large-scale battery backup system on Cape Cod is set to go online in Provincetown this summer. When it does, according to electric utility officials, power outages like the one during the Jan. 29 blizzard will be a thing of the past.
Eversource officials appeared at a Valentine’s Day select board meeting with an update on the $46-million Battery Energy Storage System (BESS) being built at the Provincetown Transfer Station. The board is investigating the local response to the blizzard, which knocked out power for thousands. While Eversource was able to restore power within 24 hours to most Provincetown customers, many asked, “Whatever happened to BESS?”
Eversource Manager of Distribution System Engineering John Ventura said that the housing is completed and most of the equipment has been installed. The next phase involves intricate testing and commissioning exercises through the spring, and the facility should be operational by July, he said.
“We want to be sure it is up and running properly by hurricane season,” Ventura said. “The batteries are in. It’s down to commissioning.”
Ventura said there would be “robust” testing of the BESS this spring that would include “brief overnight outages” lasting a few minutes, and that residents would be warned well ahead of those tests.
The BESS was designed as an alternative to running another line to Provincetown, which would have been equally expensive but more difficult to permit through the Cape Cod National Seashore, said Ventura. The battery is designed to buy time during dangerous storms when it may be unsafe for utility crews to go out and make repairs immediately.
Voters approved the project at town meeting in April 2019 and have been waiting for the backup system ever since.
The facility is the first of its kind for Eversource. Another battery planned on Martha’s Vineyard was canceled last May because of its high cost, so Provincetown’s BESS will be the first and only one of its kind for now.
According to Eversource spokesman Chris McKinnon, the BESS is a series of interconnected batteries along with a microgrid to distribute that stored energy to customers. The BESS is always connected to the grid and relies on it for charging. It stays fully charged when not providing power in an outage.
If the battery power is used up, it is disconnected and the system will recharge overnight once power is restored, McKinnon said.
The 24.9-megawatt lithium-ion battery system is designed to come online if the power fails in Provincetown, Truro, or Wellfleet, according to Eversource officials. It can provide power to all 10,000 customers in those three towns simultaneously, if necessary, they claim. Fully charged, the BESS is supposed to provide 10 hours of backup electric power in the winter and three hours in the summer. The BESS is designed to restore power to customers across the three towns. Customers closer to the battery are told to expect a more immediate restoration.
Provincetown customers will always be the first to switch to battery power, being the outermost host to the BESS, Ventura explained at Monday’s meeting.
If the battery had been up and running last fall, residents of Provincetown would not have lost power during the Oct. 27 nor’easter or the Nov. 12 storm that brought heavy rain and wind to the Cape, the Eversource officials said.
“By design, when the system is in service, the entire town of Provincetown immediately goes on to the battery system,” Ventura said. “You might see a blink or a slight dip in the voltage, but the batteries will immediately carry the town of Provincetown, and Circuit 96 gets disconnected. Customers would have had power restored in less than a minute.”
Ventura said the Jan. 29 blizzard was different from the fall storms in that there were two faults along Circuit 96 and extreme weather prevented an immediate response by Eversource line crews.
“There were whiteout conditions and heavy, sustained winds, snow packing on lines and trees, so crews could not safety go in the air,” Ventura said. “But the battery certainly would have mitigated the outage and put customers in Provincetown back in service much sooner.”
Circuit 96 is the last singular 13-mile electrical circuit on the Cape. It runs from Wellfleet into Provincetown between Routes 6 and 6A, with the bay on one side and Atlantic on the other. It is routinely pummeled by strong winds, rain, snow, and salt water, leading to a much higher incidence of failure.
“There is a lot of force being applied to our pole lines along there,” Ventura said, adding that it is one of “the worst performing circuits in all of southeastern Massachusetts.”
Another component of the BESS project is the restoration scheme. It employs 24 sensors from Provincetown to Wellfleet that feed fault location information to a computer in the BESS facility. Ventura says that the computer then isolates the fault and reconfigures the circuit to as small a pocket of customers as possible while rerouting power outside the fault area, without ever using the battery at all.
“It also isolates the location along Circuit 96, allowing us to identify the fault and respond and make repairs more quickly,” Ventura said.
He said Eversource has been routinely investing in the line, installing corrosion-resistant wires and stronger cross arms on the poles and adding “more robust insulators.”
“The chronic problems we have with that circuit are how we justified building the battery facility,” he said. “Unfortunately, you folks have lived it, we have seen it, and we are confident that once this is up and running, the experience will be much better for the residents of Provincetown and Truro and Wellfleet.”
