Eversource vs National Grid interconnection MA packages fail in the first upload when a PM reuses last week’s sketch. Boston is commonly Eversource. Worcester is National Grid. The AHJ sets can look similar: site plan, roof plan, attachment layout with dimensions, SLD with conductor and conduit notes, cut sheets, placards. The utility exhibits do not. If the cover still says the other EDC, completeness review will teach you the difference while the truck sits.
Athol Energy keeps Massachusetts jobs on the EDC named on the bill. 20,000+ residential projects and 200 MW+ designed with 30+ installer partners includes crews who run both companies in one week. That is the risk. Our Boston and Worcester pages exist so city notes stay city notes. This post is the utility half: forms and drawing mismatches, not a third city checklist.
Eversource vs National Grid interconnection MA mismatches we keep seeing
Mismatch 1: portal. Eversource Massachusetts uses its PowerClerk application flow. National Grid uses its interconnection document set and application process under M.D.P.U. 1632 (May 1, 2026). Uploading a Grid Exhibit A PDF into Eversource, or pasting Eversource seminar sketch rules into a Grid case, is how you collect a hold email that quotes a form you never filed.
Mismatch 2: Simplified size language. Eversource’s public application page currently lists Simplified non-area-network at 25 kW AC listed inverter, $0 fee on that radial path, with separate network fees and screens. Grid 1632 Simplified radial, in public excerpts, is listed inverters 25 kW or less matching service configuration plus feeder screens. Older Grid pages said 15 kW single-phase. A proposal that still quotes 15 kW on a May 2026 Grid job is a sales error. A proposal that quotes Eversource network fees on a radial Worcester job is also a sales error. [CONFIRM AS OF 2026-09-19]
Mismatch 3: sketch rules. Eversource installer sessions have said no PE stamp required on the Simplified electrical sketch, no “MIN 60A” placeholders, date your revisions, show real equipment, include UL 1741 SB if not on file. Grid wants Exhibit A plus a line diagram that matches their technical-standards samples, plus Schedule Z and other 1632 exhibits as applicable, plus ESS questionnaire for batteries. The SLD can be one drawing. The packet around it cannot.
Meters, completion, and the words for on
Mismatch 4: completion. Grid’s public Simplified article describes 10 business days for completeness, 15 for screening, conditional approval, 365 calendar days to upload completion docs, 10 days to review those, 10 days to set the meter if the site is ready, then an authority-to-interconnect email. Eversource’s public residential timeline talks in one-to-three-week application review language and a separate meter policy for PTO. Those clocks are not interchangeable in a customer email. Do not promise Grid’s ATI next-day language on an Eversource East job, or Eversource’s one-to-three weeks on a Grid hold that is waiting for Exhibit H because the system owner is not the billing name.
Mismatch 5: names on the account. Grid is explicit about Exhibit H (retail customer agreement) and Exhibit I (landowner consent) when names differ. Eversource applications also care who the customer is vs who the interconnecting customer is, plus property control if the applicant is not the owner. If your template only has one name field, you will bounce on whichever company is stricter that week. Put billing name, system owner, and landowner on the cover of the AHJ set too, so the town and the EDC are not inventing identities.
What stays the same on purpose
The equipment list. The address. The AC kW. The inverter SKU. Rapid shutdown. Production meter if SMART needs it. Battery if present. Those must match the town set for both companies. Athol’s interconnection and permit design desks freeze that list first. A fire-path cut in Boston ISD still has to hit Eversource the same day. A snow-load module cut in Worcester still has to hit Grid the same day. Statewide framing is on Massachusetts solar design services.
CSM fee, when in force under D.P.U. 26-57, is $225 Simplified on both of these IOUs in the joint proposal, with the same $10,000 benefit threshold, unlike Unitil’s $1,450. Quote it as interconnection, not as a reason the sketches became identical. They did not.
A building permit is not PTO on either company. Do not energize on a sticker. If the array moved, as-built before you ask either DG desk for a letter. Phone +1 (209) 266-2669 when the folder contains both companies’ PDFs and nobody knows which one the bill supports.
A two-EDC week that does not mix files
Name folders by EDC, not by salesperson. Boston-Eversource-address. Worcester-Grid-address. Put 1632 exhibits only in Grid folders. Put Eversource seminar checklists only in Eversource folders. If a PM copies a cover, the first QA question is “does the bill match the header?” That question has saved more install weeks than a prettier north arrow. We will not file the pretty wrong packet.
QA checklist before a mixed-territory upload
Before anyone hits submit on an eversource vs national grid interconnection ma week, we run a short, mean list. Does the bill EDC match the folder name? Does the Simplified size rule in the proposal match the tariff dated in the folder (1632 May 1, 2026 for Grid, April 27, 2026 stamp-approved set for Eversource)? Does the sketch omit placeholders? Do name fields include billing, owner, and landowner where needed? Does Schedule Z exist in the Grid folder if net metering is in play? Does the Eversource folder include UL 1741 SB if the inverter is not already on file? Did the town fire path change kW after the sketch was exported? If any answer is wrong, we do not upload.
Completion folders get the same treatment. Grid wants A2 and the commissioning memo that matches SB vs SA. Eversource wants whatever its current PTO/meter policy lists. Mixing those memos is a classic two-EDC-crew error. Label the PDF with company and address, not “final_final2.” As-builts go in if the array moved. Photos of a blocked meter do not. Fix the site, then request the tech.
City notes stay city notes. Boston ISD Short Form language does not belong in a Worcester Grid packet. Worcester Inspectional Services headers do not belong on an Eversource Cambridge cover. Utility mismatches and AHJ mismatches often arrive together because someone cloned an entire set. Clone the sheet list, not the identity block. Identity is bill, town, path, SKU, date.
Unitil and MLPs are out of this comparison except as a fail: if the bill is neither Eversource nor Grid, stop using this checklist. Third company, third folder. CSM $225 may apply to both of these IOUs on Simplified when collected, with the same $10,000 threshold in the joint 26-57 table, unlike Unitil. Quote that as money, not as proof the sketches merged. They did not merge.
Written authorization still turns the system on. Town stickers still do not. If a superintendent asks which company’s email to wait for, the answer is the company on the bill, using that company’s words (PTO or ATI). We will not energize on the other company’s template from last Thursday’s job. Put that email in the folder the day it arrives so Saturday’s crew is not guessing.
Installer questions on mixed-territory crews
The inverter is the same. Why rewrite the sketch?
Because the exhibit numbers, name fields, and completion checklists are not the same. The inverter can stay. The packet cannot.
Can one PE-stamped SLD feed both portals?
The drawing can, if SKUs match. The upload still needs that company’s forms around it. A wet stamp does not convert Exhibit A into PowerClerk.
What if the town is on the border?
The meter decides, not the town line in a sales map. Read the bill. If you cannot tell, stop and ask the customer for a statement PDF.
How do we start?
Send two jobs’ bills if you run both EDCs this week. We will keep eversource vs national grid interconnection ma files in separate folders, with one equipment list per address, so the sketch you upload is the sketch that company can approve.