Policy · Analysis

Act 179 and the 100 percent question, one filing at a time

Vermont's renewable standard requires 100 percent renewable supply by 2030 or 2035, depending on the utility. The compliance filings are where those costs first become something a ratepayer can see, and they are readable once you know the shape.

Flat geometric illustration of a Vermont dairy farm with a red barn, a large cylindrical digester tank, and cows in the pasture — An original illustration made for this publication.

BY THE CLEAN ENERGY VERMONT EDITORS · FILED OCTOBER 13, 2026 · 6 MIN READ

Start with your bill

If you pay a Green Mountain Power bill, you are already helping fund Vermont's renewable standard, even though no single line on the statement spells it out. The cost sits inside the supply charge, the part of the bill that pays for the electricity itself rather than the poles, wires, and meter reading. On any one month it is small. It is also real, and it is set to grow as the deadlines approach.

The standard is the Renewable Energy Standard, rewritten in 2024 by H.289, which became Act 179 after lawmakers overrode a veto on June 17, 2024. The short version: Green Mountain Power must reach 100 percent renewable supply by 2030, and Vermont's smaller municipal utilities and cooperatives have until 2035. The long version lives in a stack of filings at the Vermont Public Utility Commission, the state board that regulates utilities, and that is where the costs first become visible.

This desk reads those filings so you do not have to, but it helps to know what you are looking at. What follows is how a compliance filing works, where the money actually shows up, who files and who checks, and what to watch over the next month.

How a compliance filing works

Every year each regulated utility has to show the Public Utility Commission, and the Department of Public Service that represents ratepayers, that it met the standard for the prior year. The standard comes in tiers: a broad tier for total renewable energy, a tier for smaller in-state distributed generation like rooftop and community solar, and a tier known as energy transformation, where a utility helps customers cut fossil fuel use directly through things like heat pumps and weatherization. A compliance filing is the utility's accounting that it hit each tier's percentage.

The filing is backward looking, which is the first thing to keep straight. It describes a year that already happened, so it tells you what compliance cost last year, not what next year will cost. Read that way, it is less a forecast than a receipt, and the receipts are getting larger as the roughly 100 percent targets move closer.

Where the cost actually shows up

Much of the standard is met with renewable energy credits, tradable certificates that each represent the environmental attributes of one unit of renewable generation. A utility can satisfy part of the requirement by buying credits rather than by buying the matching power on your specific wire. That is why Vermont can be heavy on hydro and still trade credits across the six-state region run by ISO New England, the grid operator. The price of those credits moves, so the honest answer to what this costs is that it depends on the market in a given year.

The clearest place to watch cost pressure build is not the compliance filing itself but the rate case, the public proceeding where a utility asks to change what it charges. Compliance filings show what was spent; rate cases argue over who pays and how much. When you want to know whether Act 179 is about to touch your bill, the rate case is the document that matters, and it is argued in the open at the commission.

Who files, and who checks

Green Mountain Power is the largest utility and carries the earliest deadline, so its filings move first and draw the most attention. Behind it are the municipal utilities, including Burlington Electric Department, which has reported sourcing roughly 100 percent renewable power for years, along with Stowe Electric and others, plus the Vermont Electric Cooperative serving much of the rural north. Each files on its own, which is why there is no single statewide number you can point to in one place.

The checking is split on purpose. The Department of Public Service reviews filings on behalf of ratepayers and publishes a plain-language annual summary, while the Public Utility Commission makes the binding decisions. If a filing looks thin or a cost looks high, the department is the party expected to say so in the record, and that record is public.

Worth watching this month

1. The Department of Public Service typically posts an annual Renewable Energy Standard report summarizing utility compliance; watch publicservice.vermont.gov for the next edition, which is routine but the clearest plain-language account.

2. Any Green Mountain Power rate case or resource plan at the Public Utility Commission is where 2030 cost pressure becomes visible, so a new filing there actually matters, not just a procedural one.

3. ISO New England's regional updates on the resource mix signal how much of the region's supply is still gas, which shapes credit prices; routine, but worth a glance.

4. The Legislature usually convenes in January and may revisit Act 179 implementation; watch legislature.vermont.gov for bills that would adjust the timelines, which would be the change that moves the most.

Common questions

Does Act 179 mean my power is 100 percent renewable now?

No. The targets phase in by 2030 and 2035. Today Vermont's utilities buy a mix, and much of the renewable accounting runs through credits rather than electrons on your specific wire.

Will this raise my bill?

Probably somewhat, though by how much is uncertain and depends on credit prices and what utilities build or buy. Compliance filings and rate cases are where any increase gets argued in public before it reaches you.

What is a renewable energy credit?

It is a tradable certificate representing the environmental attributes of one unit of renewable generation. A utility can meet part of the standard by buying credits rather than the matching power itself.

Why 2030 for some utilities and 2035 for others?

The law gives Green Mountain Power, the largest, the earlier deadline and gives smaller municipal utilities and cooperatives more time, on the reasoning that larger utilities have more room to adapt quickly.

Sources of record

Vermont Public Utility Commission (state regulator): Where utility compliance filings and rate cases are docketed and decided; the primary public record.
Vermont Department of Public Service (ratepayer advocate, state agency): Publishes the annual Renewable Energy Standard report, the plainest summary of utility compliance.
Vermont General Assembly, H.289 / Act 179 of 2024: The enacted text of the renewable standard, including the 2030 and 2035 deadlines.
ISO New England (regional grid operator): Regional resource mix and system data that shape where renewable credits come from and cost.
Green Mountain Power: The largest Vermont utility, with resource plans and rate information showing how it aims to hit 2030.
U.S. Energy Information Administration, Vermont profile (.gov): Independent federal data on Vermont's generation mix for context on the starting point.

Back to the town plat