Will clustering help New England's interconnection queue?

Faced with a persistent backlog of requests to interconnect to the electric grid across parts of New England, will the region's major grid operator adopt a "clustering" methodology to streamline the study process and reduce procedural delays?

At issue are ISO New England's interconnection procedures, which govern the process through which generators and transmission lines may interconnect to the New England bulk power system.  For nearly all large projects and some smaller ones, ISO-NE administers the process and conducts extensive engineering studies to determine whether such interconnections would be feasible without adversely affecting reliability and how they should be accomplished.  In general, ISO-NE uses a first-come, first-served basis: a project's impacts on the grid are studied in sequential order based on that project's position in the interconnection queue.  In practice, this means that a project's studies do not commence until the studies for projects ahead in line are complete.

According to ISO-NE, this system has worked well for most of the region.  Excluding northern and western Maine, the grid operator reports that on average, system impact studies are completed within a year of the customer's interconnection request.  But ISO-NE notes that its "Interconnection Queue has experienced a persistent backlog of requests to interconnect in northern & western Maine."  Many of these requests relate to wind projects located relatively far from the transmission system, but similar challenges could arise relating to large solar projects in parts of Maine, Vermont, or New Hampshire.

The grid operator may be able to address this backlog by changing its interconnection procedures to be more in line those adopted in other regions, by allowing "clustering" or pooled and simultaneous study of certain resources. As described by ISO-NE in a presentation delivered last year, all of the other Independent System Operators or Regional Transmission Organizations -- such as NYISO, PJM, MISO, CAISO, and SPP - include some form of clustering in the interconnection process; New England stakeholders have requested that ISO-NE investigate clustering; and the Federal Energy Regulatory Commission has also addressed clustering, including in a May 2016 technical conference.

ISO-NE's proposed clustering methodology would allow, under specific circumstances, for two or more Interconnection Requests to be analyzed in the same System Impact Study (SIS) effort.  Projects participating in a cluster would share cost responsibility for certain shared interconnection related transmission upgrades, known as Cluster Enabling Transmission Upgrades (CETU), identified by ISO-NE as necessary for the applicable interconnection requests to interconnect.

As noted in an April 2017 presentation to the NEPOOL Participants Committee, this proposal was favorably voted by the Transmission Committee on January 24, 2017 and by the Participants Committee on February 3, 2017.

The presumptive next step forward in New England's attempt to resolve the interconnection queue backlog by clustering studies would be that ISO-NE will file its tariff revisions with the FERC -- but the grid operator has signaled an intent to wait to file the revisions until there is "a high probability of a FERC quorum."  Three of the five seats on the Commission are presently vacant, and the Commission is currently operating without a quorum.  In the meanwhile, ISO New England's present tariff does not allow clustering of studies, so for now customers and others proposing to interconnect generation or transmission into the New England grid will continue to wait and push for reform.