National Grid has selected Tesla for one of the largest energy storage project in the U.S. - 48 MWh/6 MW ESS to be installed on the island of Nantucket, 30 miles off the Massachusetts coast.

the island of Nantucket, 30 miles off the Massachusetts coast

the island of Nantucket, 30 miles off the Massachusetts coast

The ESS turns out to be the optimal solution for Nantucket, which is powered through two submarine cables that connect with the mainland transmission system on Cape Cod.

In case of a failure of one of the cables, Nantucket can count on the two 6 MW diesel generators, but generators are getting old and and need to be replaced. On the other hand growing demand for electricity will require third submarine cable within 12 years.


In the third quarter of 2017 Tesla delivered 110 MWh of energy storage (267 MWh YTD).


National Grid figured out that a better option is 48 MWh battery and one new generator that together will eliminate the need of third submarine cable for the next 27-32 years.

"National Grid explored several options to address these infrastructure needs and the ever-increasing on-island demand for electricity, and came up with a unique solution: the BESS and a new diesel generator that together can supply the island in the event of a cable failure. National Grid expects that with the BESS, the need for a third cable can be delayed for 15 to 20 years beyond the current 12-year forecast. The BESS will be six megawatts with an eight-hour duration, which is also described as a 48 megawatt-hour system, and is being provided by Tesla."

Rudy Wynter, president and COO of National Grid’s FERC-regulated Businesses said:

“The BESS provides a very efficient and effective solution to two major energy challenges facing the island. Our customers, communities, and policymakers look to us to deliver innovative solutions like this to help advance our clean energy future.”

Town of Nantucket Energy Coordinator Lauren Sinatra said:

“The Town of Nantucket commends National Grid’s decision to deploy an innovative energy storage solution on the island. We are confident that the proposed project, combined with targeted energy-saving programs and other planned electric infrastructure upgrades, will play a transformational role in meeting Nantucket’s near- and long-term energy needs.”