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Medway Grid Battery Project

EFSB 22-02/D.P.U. 22-18/22-19: On February 25, 2022, Medway Grid, LLC (“Medway Grid” or “Company”) filed a petition with the Energy Facilities Siting Board (“Siting Board”) and two petitions with the Department of Public Utilities (“Department”).

Table of Contents

Public Comment Hearing

The Siting Board conducted a remote public comment hearing regarding the Project at 7:00 p.m., on Wednesday, July 13, 2022.  A copy of the full notice can be accessed at the following link: https://fileservice.eea.comacloud.net/FileService.Api/file/FileRoom/15091206  

A recording of the public comment hearing was posted to the Department’s YouTube channel after the hearing concluded:  https://www.youtube.com/watch?v=8gid7PILV0M.

Written Comments

The Siting Board accepts written comments on the Project.  Written comments will be most useful to the Siting Board if submitted by Wednesday, July 27, 2022.

Participation in Proceedings

Persons or groups who wish to be involved in the Siting Board’s proceeding beyond providing comments at the public comment hearing or submitting written comments may seek either to intervene as a party or to participate as a limited participant.  A petition to intervene or participate must be filed in two places (see Filing Instructions below) no later than the close of business (5:00 p.m.) on Wednesday, July 27, 2022.

For those individuals and groups that are “substantially and specifically” affected by energy proposals and wish to participate actively in the proceeding, please visit the link below to learn more.

File a petition to intervene in an EFSB or DPU Siting case / Mass.gov

Filing Instructions

Written comments on the Company’s Project and petitions to intervene or participate must be filed in two places:

First, the comments or petition must be filed with the Siting Board in electronic format, by email or email attachment, to dpu.efiling@mass.gov and to robert.j.shea@mass.gov.  The text of the email must specify: (1) the docket number of the proceeding (EFSB 22-02/D.P.U. 22-18/ 22-19); (2) the name of the person or entity submitting the filing; and (3) a brief description of the document.  The electronic filing should also include the name, title, and telephone number of a person to contact in the event of questions about the filing. 

Second, all comments and petitions must be sent electronically to counsel for Medway Grid, Andrew O. Kaplan, Esq., Pierce Atwood at akaplan@pierceatwood.com, cc’d to Anne O’Hanlon at aohanlon@pierceatwood.com.

Important Dates

This section will be updated when the EFSB develops a procedural schedule for this proceeding.

July 13, 2022:  Siting Board held Public Comment Hearing

July 27, 2022:  Deadline to Petition to be Intervenor or Limited Participant/Deadline for Written Comments

Project Information

Map of Project Site

Medway Grid Project Site Map

Project Description

Medway Grid proposes to construct a 250 MW/500 MWh battery energy storage system and a new electric substation (“Project Substation”), to be located on the south side of Milford Street (Route 109) in the Town of Medway (“Project Site”).  The Project is designed to use lithium-ion batteries, which will be housed in approximately 140 above-ground enclosures on an approximately 10.6-acre lot.  Approximately 0.85 acres of the lot consists of previously developed areas associated with three existing residences and an existing automotive repair facility.  Of the 10.6-acre Project Site, approximately 5.2 acres will be developed for the BESS and the Project Substation.

The BESS will be bounded by a combination of a minimum 8-foot-high security fence in certain sections and a 22-foot-high sound attenuation barrier wall.  The sound attenuation barrier is approximately 1,280 feet in length, located along the north and east sides of the BESS.  Access gates will be locked at all times and only accessible by authorized personnel.

The function of the Project Substation is to take the power output from the BESS to a 34.5 kV collection switchgear and step it up to a transmission voltage of 345 kV, to allow the power from the BESS to be connected to the existing Eversource West Medway Substation via a proposed 1,325-foot transmission interconnection.  The proposed transmission interconnection will run underground south and west from the Project Site, crossing two Eversource-controlled parcels to connect to the Eversource substation.  The proposed underground transmission line will require the clearing of vegetation up to 25-feet-wide along its 1,325-foot corridor.  An approximately 12-foot-wide gravel roadway will be installed over the underground transmission line within this 25-foot-wide corridor to provide permanent access to the transmission interconnection. 

The Project Site is currently zoned as a Residential/Agricultural district (AR-II district), which does not allow a BESS to be constructed as of right.  Moreover, the Project involves construction of a Project Substation that will contain components which exceed the height limits of the AR-II district.  Per the Town’s by-laws, no variances or Special Permits are allowed.  The Company has therefore requested Siting Board approval of individual and comprehensive zoning exemptions from the Town’s Zoning Bylaws.

The Project was awarded a capacity supply contract from the Independent System Operator-New England based upon its ability to provide needed capacity in the Southeastern New England capacity zone by June 1, 2024, at the most competitive price.  The Project will re-charge the batteries from power supplied by the electric grid during periods of ample system supply, and dispatch electric power back onto the electric grid during times of peak demand.

Siting Board Jurisdiction

The Company filed the Siting Board petition (EFSB 22-02) pursuant to G.L. c. 164, § 69J¼, seeking permission to construct a 250 megawatt (MW), 500-megawatt hour (MWh) standalone battery energy storage system (“BESS”), including a new electric substation, on approximately 10.6 acres of land comprised of multiple adjacent parcels of land on the south side of Route 109, including a parcel at 49 Milford Street, Medway, Massachusetts (the “Project”).  Under G.L. c. 164, § 69J⅟4, the Siting Board will review the Company’s filing to determine whether the proposed Project would contribute to a reliable energy supply with a minimum impact on the environment at the lowest possible cost.  The Company filed two petitions with the Department.  D.P.U. 22-18 was filed pursuant to G.L. c. 40A, §3 (“Zoning Petition”), which requests various individual exemptions as well as a comprehensive exemption for the Project from the Town of Medway Zoning Bylaws which the Company says are necessary in order to construct the Project.  The Siting Board will review the Zoning Petition to determine whether the zoning exemptions sought are required for the Project and whether the proposed use of the land or structure is reasonably necessary for the convenience or welfare of the public.  D.P.U. 22-19 was filed pursuant to G.L. c. 164, § 72, seeking permission to construct an approximately 1,325 foot underground 345 kilovolt electric transmission line that would connect the BESS with NSTAR Electric Company d/b/a Eversource Energy (“Eversource”) existing West Medway Substation (“Section 72 Petition”).  The Siting Board will review the Section 72 Petition to determine whether it would serve the public convenience and would be consistent with the public interest.  The Siting Board will review all three petitions in once proceeding.

Project Filing with EFSB

The Company filed three related petitions with the Department, which have been consolidated into one proceeding.  The petitions for the Project include the following information: (1) a description of the Project; (2) an analysis of the need for the Project; (3) a description of the alternatives to the Project; and (4) a description of the environmental impact of the Project.

All documents filed in relation to a proceeding are posted to the DPU Fileroom The Fileroom page for a proceeding constitutes the official record for that proceeding.  The public can access the Fileroom page for this proceeding at the following link:

Accommodation Requests

The EFSB has procedures for requesting special accommodations in a proceeding.  Reasonable accommodations for people with disabilities are available upon request.  Include a complete description of the accommodation you will need and a way we can contact you if we need more information.   Please provide as much advance notice as possible.  Please allow at least two weeks (14 days) advance notice.  Last minute requests will be accepted, but we may be unable to fulfill the request. Please send your requests to: Melixza G. Esenyie, ADA and Diversity Manager at the Executive Office of Energy and Environmental Affairs at Melixza.Esenyie2@mass.gov or call 617-626-1282.

Interpretation services for those with limited English language proficiency are available upon request. Include in your request the language required, and a way to contact you if the Presiding Officer needs more information.  Please provide as much advance notice as possible.  We may not be able to accommodate last minute requests.  Contact the Presiding Officer (contact information below).


Any person desiring further information regarding this Notice, including information regarding intervention or participation in the proceeding, may contact the Presiding Officer:

Robert J. Shea, Presiding Officer

Energy Facilities Siting Board

One South Station

Boston, MA  02110



Useful Information

EFSB and DPU Siting Process

Energy facility siting laws and regulations listing

Energy Facilities Siting Board Handbook (updated 2019) | Guía para fijar la ubicación de instalaciones energéticas (2019)

Siting Related Links



EFSB/DPU Siting Division (617) 305-3525
DPU Main (617) 305-3500


(617) 443-1116


Department of Public Utilities
1 South Station, 5th floor
Boston, MA 02110

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