NSTAR, Exelon still working on interconnect for 207-MW West Medway project

NSTAR Electric on May 31 filed with the Federal Energy Regulatory Commission an executed First Amendment to a Design and Engineering Agreement with Exelon West Medway II LLC, which plans to construct an approximately 207-MW facility comprised of two simple cycle combustion turbine units in West Medway, Massachusetts.

The facility would interconnect to NSTAR Electric’s 115 kV transmission system near NSTAR’s Medway Substation #65. Exelon West Medway, NSTAR Electric and ISO New England are still in the process of completing a Standard Large Generator Interconnection Agreement (LGIA) for this project. ISO-NE has completed studies on its regional transmission system regarding the facility’s impact, and such studies identified the need for the construction of Interconnection Facilities by both Exelon West Medway and NSTAR Electric.

In December 2015, NSTAR Electric submitted for acceptance by the commission a Design and Engineering Agreement with Exelon West Medway. The purpose of that agreement was to set forth the terms and conditions under which NSTAR Electric would undertake certain design and engineering activities on the Interconnection facilities that were identified in ISO-NE’s studies, prior to execution of the LGIA.

Sections 9 and 10 of the agreement provided that it would expire no later than the effective date of the LGIA as long as that date occurs by Nov. 30, 2016, one year following full execution of the agreement. However, the agreement could be terminated at any time by either Exelon West Medway or NSTAR Electric upon 30 days’ written notice. The commission accepted the agreement on Feb. 2.

Said the May 31 NSTAR filing with FERC: “As of this filing, Exelon West Medway, NSTAR Electric and ISO-NE are continuing their efforts to develop an LGIA; however, due to the complexities of the interconnection, that undertaking is not yet complete. In response to the request of Exelon West Medway to continue to advance the implementation of its interconnection while development of the LGIA is ongoing, NSTAR Electric offered, and the parties have executed, the Amendment submitted herein. This Amendment expands the scope of the services provided by NSTAR Electric under the original Agreement to include the procurement of certain equipment that will comprise the Interconnecting Transmission Owner’s Interconnection Facilities under the LGIA, and includes updated cost estimates. The Amendment specifically provides that all other terms and conditions of the Agreement continue to remain in full force and effect.”

The project company is a subsidiary of Exelon (NYSE: EXC). The project would operate during times of peak energy demand and would run primarily on natural gas, but could also run on ultra-low-sulfur diesel (ULSD) fuel oil, ensuring fuel diversity and reliability. The project will utilize two simple-cycle General Electric LMS100 combustion turbine generators.

The project will occupy a 13-acre site within a larger 94-acre Exelon-owned property on Route 126 in Medway. The property has been used for power generation and electrical infrastructure for more than 50 years. The project will connect to the grid via an adjoining NStar Electric/Eversource 115-kV switchyard. The natural gas connection will be to the Spectra/Algonquin interstate gas pipeline which runs along the western edge of the Exelon property.

Notable is that the project is still in a review process, begun in March 2015, at the Massachusetts Energy Facilities Siting Board.

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.