THE BACKSTOP TRANSMISSION SOLUTION

BAOS: OUR “BACKSTOP” TRANSMISSION SOLUTION

As your local utilities, Eversource and National Grid have a unique role under ISO-NE’s rules for competitive development of transmission projects. The two companies must designate a single proposal as the “Backstop” transmission proposal to ISO-NE. It is important to note that this designated “Backstop” proposal, with its considerable cost and deliverability efficiencies, may be selected as the preferred competitive proposal to address the identified reliability needs for the region. However, if ISO-NE selects a proposal from a competitive developer and that developer is unable to complete the project, National Grid and Eversource would be called upon by ISO-NE to construct the backstop solution in order to maintain electric grid reliability in the Greater Boston Area.

The Boston Area Optimization Solution (BAOS) was jointly selected as the Backstop Solution as it most closely fit the criteria for the following reasons:

It has the greatest degree of schedule certainty due to minimal permitting and siting requirements. Eversource and National
Grid have all necessary property and land rights in place to construct, maintain, and operate the BAOS.

Specifically, both the series reactors and the STATCOM included in the BAOS will be sited within the companies’ substations and therefore will not require petition filings with the Massachusetts Department of Public Utilities (DPU) or Energy Facilities Siting Board (EFSB)

The solution also represents the least cost solution thereby providing significant customer savings.