Massachusetts Simplified interconnection is a tariff path with screens. It is not “the small form.” Installers lose weeks when they file Simplified on a three-phase service with single-phase inverters, or when they file Expedited because someone was scared of the word Simplified, or when they copy last year’s 15 kW single-phase rule onto a May 1, 2026 National Grid 1632 job. Pick the path the service and the listing actually support. Then draw that path.
Athol Energy files Eversource, National Grid, and Unitil applications against AHJ sets: site plan, roof plan, attachment layout with dimensions, SLD with conductor and conduit notes, cut sheets. 20,000+ residential projects and 200 MW+ designed with 30+ installer partners does not mean one PDF serves every path. Mass.gov’s interconnection page is the DPU frame. Company application pages are the split.
Massachusetts Simplified interconnection vs Expedited on the drawings
Simplified, in the DPU model and in current company pages, is the fast path for listed inverter-based facilities on radial systems under size and screen limits. Eversource’s public Massachusetts page currently puts Simplified non-area-network at 25 kW AC or less, listed inverters, $0 application fee on that radial path. National Grid’s 1632 (May 1, 2026) Simplified radial language in public excerpts is listed inverters 25 kW or less matching service configuration, plus feeder screens. Older Grid pages said 15 kW single-phase. Do not mix editions. [CONFIRM AS OF 2026-09-19]
Expedited/Standard on Eversource’s page is for systems over 25 kW AC, service-configuration mismatches, and non-inverter generators, with an application fee of $4.50 per kW (minimum $300, maximum $7,500 on that public table). IEEE 1547.1 appears in that writeup. Expedited still has screens. Failed screens move you toward Standard studies. That is not a Simplified resubmittal. That is a different clock, a different deposit, and a different one-line (often more protection, more metering, more company equipment notes).
Networks are their own Simplified variant, not a free upgrade. Eversource lists Simplified area-network and spot-network criteria, including the 1/15 of customer minimum load test, and fees on that path. Inner-core Boston-area jobs fail when the PM assumed radial Simplified because kW was 8. Check the service. Put radial vs network on the cover so the path matches the sketch.
What changes on the SLD when the path changes
Simplified still needs real devices: main breaker, meters, disconnect if installed, inverter SKUs, settings, production meter if SMART needs it, battery if present. Expedited drawings pick up more of the company’s interconnection standard: sometimes extra disconnects, relaying notes, or a three-line preference. Do not invent those extras on a Simplified house. Do not omit them on an Expedited commercial roof because the last job was Simplified. Athol’s permit design and interconnection desks scope the path at intake from the bill and the service photos.
PE stamps are still an AHJ question. Eversource seminar materials have said Simplified sketches do not need a Massachusetts PE. Expedited commercial may. The town may want a PE either way. Path name is not a substitute for the building department. Statewide context is on Massachusetts solar design services.
Fees that are not the path name
Application fees follow the path. Upgrade costs follow the screens. D.P.U. 26-57’s proposed $225 common system modification fee is aimed at Simplified applicants as a shared-cost tool, with company-specific benefit thresholds. It does not turn Expedited into Simplified. It does not belong on a SMART adder line. If it is effective when you quote, put it on Simplified proposals as interconnection cost. [CONFIRM AS OF 2026-09-19]
Company seminars split Simplified vs Expedited for a reason. Athol’s July data post noted Eversource East Simplified on September 9, 2026 and other dates for Expedited/Standard. Send the right PM. A Simplified click-path class will not teach you an Expedited screen study invoice.
How we refuse to file the wrong path
If the service is a mismatch, we will not click Simplified to save a fee. If the job is 8 kW radial listed inverter, we will not file Expedited “to be safe” and donate a $300 minimum. If the customer added a diesel generator, listed-inverter Simplified may be gone. If the battery inverter pushes combined kW over the cap, say so. Combined ratings matter on some MLP policies and on some IOU screens. Read the tariff in front of you, dated.
A building permit is not the path. PTO is not the path. The path is the application you submitted. Changing paths mid-queue is a new application in practice even if the portal lets you edit. Freeze SKUs. Pick the path. File. If the town fire path cuts kW under a threshold, you might become Simplified-eligible. Confirm before you celebrate. The feeder screen can still fail.
Screen failures, group study, and what the SLD picks up
Massachusetts Simplified interconnection ends when a screen fails, even if kW looked residential. Feeder aggregate, minimum-load tests on networks, and service-configuration mismatches are the usual kicks. When that happens, Expedited screens or Standard studies are not a personality test. They are tariff figures with deposits and time frames in business days. Read Tables in the company tariff instead of quoting a blog. Athol will not keep a Simplified cover on a job the portal already moved. Change the title block. Change the fee line. Change the customer’s calendar.
Group study language in Standard paths is a commercial/utility problem more than an 8 kW rooftop problem, but it is how a “small” ground mount becomes a year. If pre-application reports exist in the tariff, use them before you promise a Simplified week on a site the hosting map already painted as ugly. Pre-application is not an interconnection agreement. It is a paid question. Do not skip it and then act shocked at a study invoice.
Drawings on Expedited jobs often need more protection narrative: IEEE 1547.1, company interconnect standards, maybe a relay or a different disconnect. Do not copy those notes onto a Simplified house to look thorough. Extra company equipment “TBD by company” is exactly what Eversource told installers not to specify. Show customer equipment. Leave company equipment to the company unless they asked you to show a location.
AHJ electrical permits do not care what you named the path. They care about 527 CMR 12.00. A Simplified job still fails inspection on working space. An Expedited job still fails if the fire path is 22 in. Path names live in the portal. Inches live on the roof plan. Keep both honest. If kW drops under a Simplified cap after a town comment, ask the EDC whether you can truly revert paths. Do not assume. A reverted path that still fails a feeder screen is still Expedited in practice.
Seminars remain path-specific. Send Simplified people to Simplified. Send Expedited people to Expedited. IIRG meetings are where 26-57 and flexible interconnection talk happens. If you only attend click-path classes, you miss the fee. If you only attend IIRG, you miss the portal. Do both if you quote both paths. Keep a dated copy of the tariff tables in the job folder so nobody quotes last year’s Simplified size rule during an Expedited intake call.
Installer questions on path selection
The portal let me choose Simplified. Does that mean I qualify?
No. Completeness review and screening still happen. A click is not a screen pass.
Can we start Simplified and “upgrade” to Expedited later?
You can restart. You will lose time. Pick correctly from service photos and kW.
Does Unitil use the same names?
The DPU model uses the names. Unitil’s portal routes you. Use Unitil’s tariff, not Grid’s Exhibit A, not Eversource’s fee table.
How do we start?
Send the bill, service photos, AC kW, inverter listing (UL 1741 SB if required), and AHJ. Use contact or +1 (209) 266-2669. The next massachusetts simplified interconnection filing should be Simplified only if the service and the listing support it, with an SLD that would still be true if screening asks a question. If you already clicked the wrong path, say so in the first email so we restart cleanly instead of editing a doomed case.