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MassDGIC: Interconnection in Massachusetts

The Distribution Companies have issued Force Majeure notices to interconnection customers regarding impacts of the COVID-19 virus on interconnection processes. 
See the DPU's Force Majeure web page for more.

Regulatory updates on interconnection are available through the File Room for DPU-19-55 covering storage, cost allocation, qualifying facilities, smart inverters, ASO Study, timeline enforcement, and FERC vs. state jurisdictional issues.  See also the File Room for DPU-17-164 covering group study revisions made to the tariff by DPU Order on April 8, 2020.

Interconnection is the process of connecting a distributed generation system to the electric grid. Prior to connecting, the distributed generation system owner must obtain written approval from the local utility in the form of an Interconnection Service Agreement and subsequent Authorization to Connect. While emergency generators are not required to follow this process, customers installing emergency generation should contact their utility.

The interconnection process is necessary to protect the reliability and safety of the electric grid. The Massachusetts Department of Public Utilities (DPU) regulates this process by requiring utilities to have standardized interconnection tariffs (links to the Interconnection Tariffs in effect as of March 15, 2017, are available at the right of the page).

Utility Reporting & Circuit Analysis for Locational Value

In compliance with DPU Order 11-75-E (see DPU File Room) and consistent with the DG Working Group Report filed in that proceeding, on the 15th of each month the electric utilities provide monthly reporting on projects following the Expedited and Standard processes (this data does not include projects following the Simplified process).  The links below take users to a preview screen on Google Drive (choose "file" and "download" for the entire file):  
  • Download the RAW DATA set through May 2020 (posted 6/17/20). We are now releasing the raw data as soon as it's produced while the Full Data with circuit analysis is in process.
  • Download the FULL DATA set through April 2020 (posted 5/26/20) to see data reported on a project-by-project basis, now with circuits named and ability to view by municipality to enable developers seeking high value and low cost locations for solar and storage.  Note: The FULL DATA set is the result of an analysis conducted by DOER and is typically available no later than the first of the following month (2 weeks after the utilities provide reporting on the 15th of each month).

As of November 2019, the electric utilities in Massachusetts are now making Hosting Capacity Maps available for review (still in development).

Mapping Circuit Saturation

The map below displays the levels of saturation by town using the above FULL DATA set (through March 2020 -- updated 4/30/20).  Click on the map to adjust the filters by utility and/or town. This analysis will be updated monthly on the same cycle with utility reporting.  (see further description below.)

The colored dots indicate the percentage of circuits serving that town that are estimated to be saturated enough to cause potential grid upgrades for larger distributed energy projects under utility study. As is stated in the FULL DATA instructions (downloadable from the link above), a general rule of thumb has been applied on a premise that 3 MW of Expedited and Standard Review may trigger costly upgrades (understanding the utilities leave a roughly equal amount of space for projects following the Simplified Process). Please note: The utilities have not indicated the true hosting capacity of each of their circuits and do not currently report which circuits have received upgrades, making room for more distributed energy.

Circuit Analysis Downloads

The Circuit Analysis Downloads chart, above, depicts how many times the Full Data set of circuit analysis has been downloaded since November 2017 (DOER has tracked download numbers since April 2017).  Developers can also find circuit and substation data in the Resources to Aid Siting of Distributed Generation section of the Distributed Generation Working Group page (the most recent 2018 data became public in April 2019).

Interconnection Activity
Massachusetts utilities provide monthly reporting on the status of all interconnection applications submitted since January 2009 that follow the expedited or standard review process. The charts below provide an overview of the type and quantity of distributed generation projects that have entered or completed the interconnection process through 2016

Note: The graphs and full data set provided below cover only applications that follow the expedited or standard review processes. They do not include those applications that follow the simplified review process for smaller systems.

NOTE: On March 13, 2013, the DPU issued an Order (DPU 11-75-E) approving the Timeline of the recommendations in the DG Working Group Report and directed the utilities to file compliance tariffs within 30 days (stamp approved on May 2, 2013).  On July 31, 2014, the DPU issued an Order (DPU 11-75-F) approving a Utility Timeline Enforcement Mechanism filed by DOER and the utilities.  More background materials about this Order are available at the Distributed Generation Working Group web page.  Starting December 2014 DOER added new Interactive Charts on Utility Performance and Enforcement (see below).

For an overview of the interconnection process, please review the Frequently Asked Questions and a recent utilities' interconnection process workshop presentation

The detailed legal and engineering requirements for the interconnection process are set out in each utility's interconnection tariff (see links in right sidebar). For certain technical requirements not addressed in the tariff, see also the materials featured on the web page of the MA Technical Standards Review Group.

An interconnection project can follow three possible review paths: simplified, expedited, and standard. The path followed is primarily determined by the technology, size, and complexity of the project. 

Since the DPU and DG Working Group members are utilizing this information for performance tracking DOER also provides an update on the status of reporting.
DOER Reporting Update (5/2/13)

On-Site Generating Facilities Reports 

2018 On-Site Generating Facilities Report (filed with DPU by 4/1/18)

2017 On-Site Generating Facilities Report (filed with DPU by 4/1/17)

2016 On-Site Generating Facilities Report (filed with DPU 4/1/17)

2015 On-Site Generating Facilities Report (filed with DPU 4/1/16)

2014 On-Site Generating Facilities Report (filed with DPU 4/1/15)

2012 On-Site Generating Facilities Report (filed with DPU 4/1/13)

2011 On-Site Generating Facilities Report (filed with DPU 4/1/12)

2010 On-Site Generating Facilities Report (filed with DPU 4/1/11)

2009 On-Site Generating Facilities Report (filed with DPU 4/1/10)

2008 On-Site Generating Facilities Report (filed with DPU 4/1/09)

2007 On-Site Generating Facilities Report

2006 On-Site Generating Facilities Report (xls data file)

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Additional Information


Utility Tariffs
Eversource Website 
   - NSTAR Tariff

   - WMECo Tariff

NOTE: The above tariffs are the ones effective as of March 13, 2017 as a result of DPU docket 11-75 on interconnection. For more information, see the DPU File Room.