ISO New England files new interconnect deal for uprated Granite Ridge plant

ISO New England, New England Power d/b/a National Grid and Eversource Energy Service Co. on behalf of its affiliate Public Service Co. of New Hampshire, on Sept. 30 filed with the Federal Energy Regulatory Commission an executed non-conforming Standard Large Generator Interconnection Agreement with power plant operator Granite Ridge Energy LLC.

The Granite Ridge plant is an existing facility consisting of two combustion turbine units (CTG#1 and CTG#2) and one steam turbine unit (STG) operated in single combined cycle configuration, and located in Londonderry, New Hampshire. The facility had a commercial operation date in 2003. Its interconnection to the system is unique in that, while the facility operates in a single combined cycle configuration such that the individual units comprising the unit cannot be separated, its CTGs and the STG were originally interconnected to two different portions of the system.

The Sept. 30 filing noted: “On November 18, 2014 (and as subsequently revised), Granite Ridge submitted an Interconnection Request under Schedule 22 of the ISO OATT to increase the net megawatt (‘MW’) output of the Large Generating Facility and the associated Interconnection Services–Capacity Network Resource Interconnection Service and Network Resource Interconnection Service. With the proposed increase, the Large Generating Facility will be rated at 827 MW gross and 812 MW net, with the CTG#1 and CTG#2 each rated at 271.5 MW net and the STG rated at 269 MW net. Consistent with Order No. 2003 and Schedule 22, this request warranted a new pro forma LGIA. Because of the Large Generating Facility’s operation as a single combined cycle unit, the ISO, with NEP, PSNH and Granite Ridge’s concurrence, determined that the CTGs and STG interconnections to the Administered Transmission System needed to be governed by a single Large Generator Interconnection Agreement that, while based on the form of the pro forma LGIA, would recognize the Large Generating Facility’s unique interconnection to the system.”

Power plant operator contact information in the agreement includes: Granite Ridge Energy LLC, 21 North Wentworth Avenue, Londonderry, NH 03053, Attention: Plant Manager, Facsimile: (603) 437-8449, E-mail: and

About Barry Cassell 20414 Articles
Barry Cassell is Chief Analyst for GenerationHub covering coal and emission controls issues, projects and policy. He has covered the coal and power generation industry for more than 24 years, beginning in November 2011 at GenerationHub and prior to that as editor of SNL Energy’s Coal Report. He was formerly with Coal Outlook for 15 years as the publication’s editor and contributing writer, and prior to that he was editor of Coal & Synfuels Technology and associate editor of The Energy Report. He has a bachelor’s degree from Central Michigan University.