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National Grid solar interconnection: what it requires before you energize
How does National Grid detect unpermitted backfeed?
Being verified being verified
What happens if they catch you?
Being verified being verified
Small and DIY interconnection requirements
Simplified track for small systems with a $28 application fee: apply, receive initial acceptance, install, then verification or witness testing before final approval to operate. A fresh interconnection tariff (MDPU 1579) took effect April 2025. documented
MA netting is among the strongest anywhere: credits include supply, distribution, and transmission components, and they roll forward indefinitely. The Schedule Z form lets you allocate credits to other accounts in the same load zone. documented
DIY-friendly touch: National Grid publishes sample one-line diagrams for residential PV, including a microinverter version, so you can match the expected format exactly. documented
Move trap from their own FAQ: credits transfer only if you stay in their territory and the same ISO-NE load zone. Move out of state, to another utility, or across load zones, and your banked credits are forfeited. documented
sources: National Grid MA interconnection documents · Mass.gov net metering guide
Related: Eversource (MA / CT) · Knoxville Utilities Board (TN (TVA LPC))
Planning a zero-export or plug-in setup here? See the zero-export reality check and equipment notes.
Every claim above is evidence-graded: documented means it traces to the tariff or the utility's own filings, reported means a dated community report. The full table covers 53 utilities: see all of Gridrules.