There are thousands of islands around the world that have no access to a conventional utility grid. Most of them rely on diesel generators for their electricity. Trendy Nantucket, once home to the world’s largest whaling fleet, is connected to the onshore grid by two undersea cables but it also relies on diesel generators for backup power in case one of those cables fails.
As more and more people choose Nantucket as a place to hobnob with the rich and famous during the summer months, the demand for electricity has grown. In addition, the backup generators are nearing the end of their useful life and will need to be replaced in the foreseeable future. National Grid, the utility company that supplies electricity to Nantucket, was faced with the cost of adding a third undersea transmission cable or buying two new generators. Instead, it has decided to invest its money in a grid-scale battery installation. It has struck a deal with Tesla to install 200 of its Powerpack batteries on the island with a total storage capacity of 48 MWh and one new generator.
“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 [battery energy storage system] and a new diesel generator that together can supply the island in the event of a cable failure,” says National Grid in a press release. “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, adds, “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.”
The installation on Nantucket will be funded in part by a $4.7 million grant from the Department of Energy Resources for companies that demonstrate innovation in peak electricity and gas demand reduction in Massachusetts. “Today’s grants will ensure that the Commonwealth remains at the forefront of energy innovation by utilizing emerging technologies to reduce peak energy usage,” Lieutenant Governor Karyn Polito said in June when the grants were announced.
$996,455 of that grant was awarded to Tesla. It called for a project that would increase energy storage in order to lower peak demand within a National Grid territory. “Tesla will work to quantify the benefits of the demonstrated peak demand reductions and evaluate the model’s viability at scale,” says the Energy Resources department.
Tesla is certainly on a roll when it comes to supplying offshore islands with electricity. It has completed installations on Kauai and in Samoa and is working overtime to help Puerto Rico recover after Hurricane Maria. Nantucket may be a small project in the grand scheme of things, but it points the way to a brighter, cleaner, low-carbon future for many island residents around the world.