Grid · Analysis

The lines from Quebec carry Vermont's winter

Hydro-Quebec imports are the quiet backbone of the state's grid. Here is how the contracts work, why winter leans on them, and what reservoir levels have to do with your bill.

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 26, 2026 · 6 MIN READ

How the Quebec power reaches your meter

The physical path starts at the Highgate converter station in Franklin County, near the Canadian line, where high-voltage direct current (power sent as a steady one-way flow, which travels long distances with less loss than ordinary alternating current) is turned back into the alternating current the regional grid uses. A second, larger high-voltage direct current line, the Phase II interconnection built in the late 1980s, runs down through Vermont toward a converter in Massachusetts, so some of the power crossing the state is only passing through on its way elsewhere.

Commercially, the picture is separate from the wires. Vermont utilities, led by Green Mountain Power, hold long-term purchase contracts with Hydro-Quebec, the provincial crown corporation that owns most of Quebec's dams. At last public report those contracts run into the late 2030s, which is why the imports count as firm, year-round supply rather than spot-market purchases that could vanish when prices spike.

The honest math, and where the water comes in

Put a rough number on it: Hydro-Quebec has supplied on the order of a quarter of Vermont's electricity in recent years, per state energy reporting, though the exact share moves from year to year. That is a large block of carbon-free power at a price set in advance, which is part of why Vermont's rates have held steadier than those of states leaning harder on natural gas, where winter fuel costs can swing hard.

Hydrology is the catch. Hydro-Quebec generates from reservoirs, and in a dry year those reservoirs refill more slowly, which can tighten how much the utility is willing or able to export. Vermont's contracts are written to deliver firm amounts, so a single dry season is unlikely to leave anyone cold, but a run of low-water years is the kind of thing that shows up in long-range planning rather than next month's bill.

Who holds the contracts, and who watches them

Green Mountain Power serves most of the state and carries the largest share of the Quebec contracts; smaller municipal utilities and cooperatives buy in through their own arrangements and through statewide purchasing. Hydro-Quebec sits on the other side of every one of those deals, and because it is owned by the Province of Quebec, its export decisions are as much political as commercial.

Within Vermont, the Public Utility Commission approves the contracts and the rates that flow from them, while the Department of Public Service represents ratepayers in those cases. ISO New England, the nonprofit that runs the six-state grid, schedules the imports into the regional system day to day. If you want to know whether a contract is sound, those are the three bodies whose filings will tell you.

Worth watching this month

1. Watch ISO New England's winter outlook, usually published ahead of the cold season, for how much it is counting on imports to cover peak demand.

2. Keep an eye on any Public Utility Commission docket touching Green Mountain Power's power-supply contracts, since renewals and amendments are reviewed in public.

3. Hydro-Quebec's periodic reservoir and generation reports are the clearest public signal of whether a dry year is building north of the border.

4. Vermont's annual state energy data will update the Quebec share when it lands, and is worth checking against the rough quarter cited above.

5. Any hard cold snap this winter is a live test of the import lines, so note whether ISO New England issues conservation or capacity alerts, which are routine in some winters and genuinely serious in others.

Common questions

Does Hydro-Quebec power show up on my bill?

Not as its own line. It is folded into the supply portion of your utility's rate, which is set through long-term contracts and approved by state regulators.

Is Vermont too dependent on Canada for power?

It depends on how you weigh steady prices against relying on one supplier. The contracts are firm and long-dated, but a long stretch of dry years in Quebec is the risk planners watch.

Could a cold snap cut off the imports?

A single cold snap is unlikely to, since the contracts call for firm delivery and the lines are built for winter. The larger question is regional gas supply, which ISO New England leans on alongside imports during peaks.

Where does the power physically cross into Vermont?

Mainly at the Highgate converter station in Franklin County. A larger high-voltage direct current line also runs through the state toward Massachusetts, carrying power that is largely passing through.

Sources of record

ISO New England (regional grid operator): The nonprofit that runs the six-state grid; winter outlooks, real-time conditions, and how imports are scheduled.
Hydro-Quebec: The exporter itself; company pages on generation, reservoirs, and exports to New England.
Green Mountain Power: Vermont's largest utility; power-supply and rate information, including its Hydro-Quebec purchases.
Vermont Public Utility Commission (.gov): State regulator that reviews and approves utility contracts and the rates that follow from them.
Vermont Department of Public Service (.gov): Represents ratepayers in commission cases and publishes the state's energy planning and data.
U.S. Energy Information Administration, Vermont profile (.gov): Federal electricity profile for Vermont, including generation mix and the import share over time.

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