ISO-NE, NEPOOL, and PTO AC make joint filing regarding the interconnection clustering methodology
Update 11/1/2017: FERC has issued its order accepting the interconnection queue clustering revisions. FERC rejected all protests and determined that the clustering revisions increase efficiencies, better inform the decisions of project developers, and allow project developers to share the costs of the upgrades necessary to accommodate their interconnection. By allowing interconnection requests to be studied in a cluster, the clustering revisions should provide a means to relieve the queue backlog in northern and western Maine, which is one of the primary obstacles to interconnections in that region.
ISO New England, jointly with the New England Power Pool Participants Committee and the Participating Transmission Owners Administrative Committee, has filed proposed tariff changes to incorporate a new clustering methodology in the ISO’s interconnection procedures. When specific conditions are present in the ISO’s interconnection queue, the proposed methodology would allow two or more interconnection requests to be analyzed in the same System Impact Study and for developers to share costs for certain interconnection-related transmission upgrades. Typically, each individual interconnection request involves complex and often lengthy engineering studies to identify the necessary system upgrades to accommodate the proposed resource. Therefore at times, individual interconnection projects are not able or willing to make the necessary system upgrade investments.
The filing parties propose to first implement the clustering methodology to help move forward the backlog of interconnection requests experienced in Northern and Western Maine, where more than 5,800 megawatts of proposed new resources, mostly wind, are seeking to interconnect to the regional grid. Significant new transmission infrastructure is required for this level of additional resource interconnections. The Northern and Western Maine areas of the system are comprised of a transmission network that was built to serve low levels of area load, and a number of generators are already connected to this part of the system, leaving this part of the transmission system at its performance limit with no remaining margin.
Though the proposed clustering methodology has been developed to address the backlog in Northern and Western Maine, the methodology would be available for use whenever similar circumstances are present.