Massachusetts board working on review of 200-MW West Medway II project

The Massachusetts Energy Facilities Siting Board is taking comment on a Final Environmental Impact Report (FEIR), filed on Feb. 1, for the proposed 200-MW West Medway II project in Medway, Mass.

Since the Secretary of Energy and Environmental Affairs issued a Certificate on the Draft Environmental Impact Report (DEIR) for the project in November 2015, Exelon West Medway LLC and Exelon West Medway II LLC have continued to advance the project design and development effort. These companies are subsidiaries of Exelon (NYSE: EXC).

The FEIR noted that the project companies have signed a Host Community Agreement with the Town of Medway and have reached agreement on a Payment In Lieu Of Taxes (PILOT) measure with the Medway Board of Selectmen. Working under contract to the Town of Millis and Exelon, the engineering and planning firm Kleinfelder has completed a study of the Millis water system with respect to providing supplemental water to the plant. The draft stormwater report has been issued and further work on the greenhouse gas (GHG) emissions analysis has been completed. 

The project is a new, highly efficient, fast-starting 200-MW peaking plant. It 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 most efficient simple-cycle generator available on the market, said the FEIR.

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.

The FEIR said: “The Project has successfully bid into ISO-NE’s Forward Capacity Auction #9 and is scheduled to begin operation by June 2018. The Project will provide additional needed capacity to the Southeast Massachusetts–Rhode Island load zone in the ISO-New England electric grid while supporting the growth of renewable energy in Massachusetts by providing a quick-starting back-up for intermittent renewable energy sources such as solar and wind.”

Progress made in recent months in the public review process

The FEIR added: “Since the September 30, 2015 submittal of the DEIR, the Project has continued to make good progress on a number of fronts. An independent group of attorneys, engineers and environmental scientists retained by the Town of Medway completed a thorough review of the Project and presented their findings at a well-attended public meeting. In mid-October, the project signed a Host Community Agreement with the Town of Medway. The Project and the Medway Selectmen also reached agreement on a PILOT agreement that will bring approximately $75 million to the Town over a twenty year period (pending Town Meeting approval). Through the fall and early winter, the Project team completed a rigorous EFSB discovery process. Eleven days of evidentiary hearings were just concluded and the team is looking forward to moving into the briefing process. Local permit applications are being completed for submittal within a few months. Please notice the FEIR in the Environmental Monitor to be published on February 10, 2016. We understand that the public comment period will extend through March 11, 2016, and the Certificate will issue on March 18, 2016.”

Use of ULSD will be limited to an equivalent of 30 days/720 hours per year. The companies expect the project will operate on average 10 days per year on ULSD. Pollution control equipment would include Selective Catalytic Reduction and carbon monoxide oxidation catalysts in modules downstream of each CTG.

A new approximately 3,080-foot-long, 12-inch diameter gas interconnection pipeline will be permitted and constructed by Exelon. ULSD fuel oil will be transported to the site from a Providence, Rhode Island, terminal, following the same truck-based delivery practices as used for the existing ULSD-fired station on the property. 

Exelon participated in the ISO-NE’s FCA #9 on Feb. 2, 2015, with a bid for a 195 MW peaking project to sell power to the SEMA/RI load zone. The bid “cleared,” which means the project holds a supply obligation in the ISO-NE capacity market. This means that beginning in June 2018, if ISO-NE calls upon the project to run and produce power, it must do so or it may be required to pay back a portion or more than its entire capacity payments through performance penalty payments.

The very low heat rate (i.e., high efficiency) of the GE units means that they will likely be dispatched by NE-ISO more often than traditional peaking units. Under certain operating circumstances, it is possible that the project could be dispatched up to 60% in a given year. However, in accordance with recently updated New Source Performance Standards (NSPS), the three-year rolling average capacity factor of each turbine will be limited to 43%. Accordingly, if the project operates at 60% capacity factor for its first full year of service, operations over the next two years would be limited to an average capacity factor of 34.5% (yielding a three-year rolling average of 43%).

In other recent developments for this project:

  • NSTAR Electric on Dec. 11 filed with the Federal Energy Regulatory Commission an executed Design and Engineering Agreement with Exelon West Medway II for the interconnection facilities needed for this project.
  • General Electric (NYSE: GE) announced on Dec. 8 that it is providing Exelon with two highly efficient LMS100PA+ aeroderivative gas turbines for the West Medway project. The existing Medway units will continue to operate.
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.