National Grid has long recognized the important role renewable energy is playing in our clean energy transition and we’ve been a leader in supporting the integration of those resources into our network. Our team has been making it happen, helping to deeply decarbonize our regional power system. As solar has taken off in our New England service territory, National Grid has worked with the industry to overcome countless challenges and ensure the reliability of our system, one that wasn’t built for distributed resources.   

State policy-driven incentive programs have fostered an unprecedented volume of large and complex distributed generation (DG) interconnection applications in

Massachusetts and Rhode Island in recent years.  In some areas, the massive surge of complex applications has resulted in oversaturation and potential impacts to neighboring electric power systems, both at a transmission and distribution level.

Beginning in 2019, our system reached saturation in a number of areas and we could not interconnect certain DG systems until detailed studies of the impacted distribution and transmission networks were completed, approved by ISO-NE, and the necessary modifications or upgrades, if any, were fully understood and constructed.

Typically, such studies would be done sequentially for each individual customer, which in this case would have resulted in over 200 studies, taking years to work through all of them. Instead, National Grid’s Transmission Planning team proposed one large study, commonly referred to as the “cluster study.” 

National Grid recently received approval from ISO-NE to interconnect 617 megawatts (MW) of DG across its Massachusetts and Rhode Island service territory – a record. The approval follows the completion of the second phase of the cluster study and included two major transmission system area analyses. This was a first-of-its-kind streamlined approach to understand the impact hundreds of interconnection points have on the electric transmission networks in Massachusetts and Rhode Island.

For more information on the Cluster Study process or the Company’s approach to distributed generation, please contact National Grid’s recently appointed DG Ombudsperson Michael Porcaro.

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