The Massachusetts Energy Facilities Siting Board on Nov. 18 approved a petition from Exelon West Medway LLC and Exelon West Medway II LLC to construct a 200-MW simple-cycle dual-fueled facility on the site of an existing Exelon generating facility on Summer Street in the town of Medway, Massachusetts.
Tthe Siting Board also approved Exelon’s petition for certain exemptions from the Town of Medway Zoning Bylaw.
The Exelon Corp. (NYSE: EXC) subsidiaries propose to locate the facility on an approximately 13-acre site within a larger 94-acre Exelon-owned site on Summer Street in Medway. The Summer Street site currently contains an existing Exelon West Medway LLC. NSTAR Electric Co. d/b/a Eversource Energy uses 54 acres of the Summer Street site, to the west of the existing and proposed facility sites.
The existing facility consists of three peaking units fueled by ultra low sulfur distillate (ULSD) fuel oil, with a combined capacity of 135 MW. The existing facility has been in operation on the Summer Street site since 1970. In 2000, the Siting Board approved the construction of a 540-MW peaking facility on the site, proposed by Sithe Energies. That facility was never built.
The existing facility has been owned and operated by Exelon West Medway LLC since 2002. The proposed facility would be owned and operated by Exelon West Medway II LLC.
The new facility would be a dual-fuel (natural gas and ULSD), simple-cycle, quick-start, peaking facility, capable of generating 200 MW (nominal). The main components are two General Electric LMS100 simple-cycle peaking combustion turbine generators (CTGs), each with a net nominal output of 100 MW. The turbines would be equipped with pollution control equipment including selective catalytic reduction (SCR) and carbon monoxide (CO) oxidation catalysts, closed-cycle dry cooling, and noise attenuation features. The company has proposed the installation of two 160-foot-high exhaust stacks for the turbines.
The company stated that the primary purpose of this new facility is to provide additional capacity for the Southeastern Massachusetts/Rhode Island (SEMA/RI) load zone in the ISO New England region to meet peaking needs. The facility also would provide quick-starting back-up for intermittent renewable energy sources such as wind and solar. Exelon successfully bid 195 MW of capacity into ISO-NE’s Forward Capacity Auction (FCA) in February 2015. Exelon’s capacity supply obligation begins on June 1, 2018, and this proposed facility is obligated to be available to produce electricity by that date.
The Federal Energy Regulatory Commission on Oct. 27 approved a Sept. 30 application from Exelon West Medway II for market-based rate authority. The company told FERC it anticipates that sale of test power from the facility could begin as early as December 2017, with commercial operation expected in April 2018.