Rules by state

Solar and battery interconnection rules in Vermont

Vermont interconnection procedures and net metering. Every threshold below was read out of the document linked at the bottom of this page, and the same rules answer the free screening check.

Who this binds: investor owned utilities, municipal utilities, electric cooperatives.

Check a Vermont address free
How the size is measured

capacity: the rated electrical nameplate, except that for a solar energy plant it is the aggregate alternating current nameplate capacity of all inverters used to convert the output to alternating current. The capacity of an inverter is not changed when it is derated. That last sentence is the Vermont trap: a project held to a fifteen kilowatt limit cannot be built with a larger inverter field clamped in firmware.

Size bands and what each one obliges

Category I Size 0 to 15 kW

A net metering system of 15 kW or less that is not hydroelectric. Registration is available, and a certificate of public good is deemed issued without further proceedings on the fifteenth day after filing, so construction may begin then. For a system up to 15 kW the registration form also counts as the interconnection application.

  • Registration filing
  • Certificate of public good deemed issued on the fifteenth day
Category II, preferred site Size 15.001 to 150 kW

More than 15 kW and not more than 150 kW on a preferred site. Above 15 kW the order reverses: interconnection approval under Rule 5.500 must be obtained before a registration form is filed. A ground mounted system needs an advance submission at least 45 days before filing the application.

  • Interconnection approval before registration
  • Advance submission at least 45 days ahead for the application track
Category III, preferred site Size 150.001 to 500 kW

Greater than 150 kW and not more than 500 kW on a preferred site. The application fee for interconnection is $600 above 150 kW, or the amount in an approved utility tariff; below 150 kW there is no fee unless a tariff provides one.

  • $600 interconnection application fee above 150 kW
  • Certificate of public good

The screens that decide it

Ask the utility this, before you sell it

  1. Is the ground mount registration threshold 15 or 25 kilowatts for this project? Act 38 raised it to 25 kilowatts effective 1 July 2025 and directed the Commission to allow expedited registration for systems of 25 kilowatts and less before the rules are updated, but the March 2024 rule still says 15 kilowatts throughout. A tool reading only the rule will wrongly push a 16 to 25 kilowatt ground mount into the slower certificate track.
  2. Is a locational adjustor fee charged at this address? Vermont authorizes a per kilowatt fee on new systems in constrained or limited headroom areas, collected before the system is energized, and the boundaries sit in each utility tariff rather than in the rule.
  3. What is the export limiting method and its setting? Vermont publishes seven accepted methods with default settings, including a relative rating option requiring the project to be no greater than fifty percent of verifiable minimum host load over the past twelve months.

Worth knowing before you quote

Vermont publishes no insurance requirement at any size. Neither Rule 5.500 nor Rule 5.100 contains an insurance or indemnification section, verified by searching both. It publishes no aggregate net metering cap either; the program is throttled through rates, biennial updates and the locational adjustor fee instead. Vermont deleted the fifteen percent screen in the 2024 revision and its current preliminary screening criteria are thermal and protection based rather than penetration based, so any Vermont fifteen percent rule is coming from the superseded 2006 document that is still posted on the Commission site. A screen failure is also not a stop in Vermont: the rule permits approval despite failure with written technical justification.

Source

Vermont Public Utility Commission Rule 5.500, interconnection procedures for proposed electric generation resources and energy storage devices, revised 1 March 2024, and Rule 5.100 on net metering systems, with 2025 Act 38

Read and recorded 2026-09-12. Rule 5.500 applies to all proposed interconnections within Vermont that are not subject to regional transmission organization rules, and contains no carve-out for municipals or cooperatives. Unlike Rhode Island, Vermont does not exempt its consumer owned utilities, so Washington Electric Cooperative, Vermont Electric Cooperative and the municipal departments are inside the same rule. Vermont also requires a certificate of public good before construction, so a screen must model that gate as well as interconnection.

What to do with this

Check a real address

The rules below are the general case. Run the free check to see which utility serves a specific address, which tier the system lands in, and what to ask.

Run the free check
Installers: keep the answer with the job

GridProjeX holds the project from here, with every value tied to the document it came from and the utility and permit tracks run to permission to operate.

How it works for installers
Utilities: see what applicants are told

The same published rules your applicants read here are the ones your queue sees. GridProjeX is the record both sides work from.

How it works for utilities

Also from CivyxIQ, if they fit what you already do: SolarProjeX for running the crews and the jobs, and Solar Home so the homeowner can follow their own project. Neither is needed to use the checker.