National Grid (Massachusetts) interconnection application

Documents National Grid (Massachusetts) asks for

• Interconnection application formExhibit A Simplified Interconnection Application (M.D.P.U. 1646, 11/1/2026), webform with e-signature, signature & date required Gridpol prepares this.
• Site plan / site layoutTo scale with scale bar, north arrow, property lines, streets, all meters, isolation device, PCC, nearest pole number, existing systems (ESB 756 C 5.1.4) Gridpol prepares this.
• Single-line diagram (one-line)Line diagram; equipment must match application and Equipment Selector; required notes on grouped/lockable metering and disconnects; ESS charge/discharge and derating notes Gridpol prepares this.
• PV module spec sheetTechnical specification sheets for all equipment
• Inverter spec sheetPlus UL 1741 SB certificate
• Battery spec sheet (when applicable)ESS Questionnaire (webform) + cut sheets; total ESS kWh and AC/DC coupling must match
• Net metering / net billing agreement (when applicable)Schedule Z (M.D.P.U. 1646) for net metering
• Other utility-specific document (when applicable)Exhibit H Retail Customer Agreement if billing account holder is not system owner; Exhibit I Landowner Consent; curtailment/derating letter on manufacturer letterhead if system larger than export
• Final inspection sign-offExhibit A2 Certificate of Completion + Simplified Process Completion Documentation Checklist + commissioning memo
• Photos (meter, main panel, equipment) (when applicable)PV plaques must be visible in pictures accompanying completion documentation

How the National Grid (Massachusetts) process runs

1. (If new/upgraded service needed, request it first.) Installer submits Simplified Process application (Exhibit A) with supporting documents through the utility portal.
2. Utility acknowledges receipt within 3 business days; completeness determination within 10 business days.
3. Utility completes screens within 15 business days (20 if Screen 5 fails); total max 25 business days (30 with Screen 5 failure).
4. Utility countersigns application approval line = Conditional Approval to Interconnect (minor system modifications billed if needed).
5. Install facility; local electrical wiring inspector signs Certificate of Completion (installing electrical contractor also completes it).
6. Return Certificate of Completion (and completion documentation); utility may perform Witness Test within 10 business days or it is deemed waived.
7. Meter installation; utility issues Authorization to Interconnect within 5 business days after requirements met and meter installed. No parallel operation before Authorization to Interconnect.

Fees

Utility fees are paid by the installer or customer; they are not part of the Gridpol plan.

Size levels and limits

Storage, EV and stamps

Common issues the utility lists

• Equipment on line diagram not matching application/Equipment Selector/completion documentation
• Missing ESS Questionnaire or ESS data mismatch (kWh, AC/DC coupling, aggregate size)
• Address mismatch between portal, site plan and application
• Missing required one-line notes (grouped, outside, 24/7 lockable metering and disconnects)
• PV plaques not visible in completion photos

Gridpol’s pre-submission check covers these before we file.

Sources

• National Grid Customer Application Portal - MA Interconnection Documents (Oct 29, 2026): https://gridforce.my.site.com/s/article/MA-Interconnection-Documents (retrieved 2026-11-13)
• National Grid - Application Checklist for Simple and Expedited (08/19/2026): https://gridforce.my.site.com/servlet/servlet.FileDownload?file=015Vw00000Udltp (retrieved 2026-11-13)
• MA DPU standard interconnection tariff (Eversource M.D.P.U. 55G) - uniform Simplified Process timelines: https://www.eversource.com/docs/default-source/rates-tariffs/mdpu-55a-interconnection-distributed-generation.pdf?sfvrsn=897b4555_4 (retrieved 2026-11-13)