Interties are high-voltage transmission lines that connect one province's grid to another's, or to a neighbouring U.S. state. They let regions share electricity: a province with surplus hydro can sell it to a neighbour, and a province facing a cold snap or a plant outage can import power instead of building extra capacity. Canada's grids have historically been better connected north–south to the United States than east–west to each other, and federal and provincial governments are now prioritizing new links between provinces.
Key takeaways
- An intertie is a transmission connection between two separate grids, letting them trade power and back each other up.
- Each Canadian province runs its own grid, and many trade more electricity with U.S. neighbours than with other provinces.
- Interties improve reliability, lower costs and make it easier to add wind and solar by spreading out weather-related ups and downs.
- In 2026, governments named five priority interprovincial interties, including Alberta–B.C. and Saskatchewan–Manitoba.
- Building new interties is slow and expensive, and deciding who pays is often the hardest part.
What an intertie does
Picture each provincial grid as an island. An intertie is a bridge. With bridges in place, islands can:
- Share reserves: If a large plant trips offline, neighbours can send power within seconds, so each province doesn't need to hold as much backup.
- Trade economically: A province with cheap surplus power can sell it to a neighbour that would otherwise run a more expensive plant.
- Smooth out renewables: The wind may be calm in one region and strong in another. Larger, connected areas balance wind and solar more easily.
- Use storage they don't own: Hydro-rich provinces can act like a giant battery for neighbours, absorbing surplus power and sending it back later.
Interties come in two main types: alternating current (AC) lines that tie grids together synchronously, and high-voltage direct current (HVDC) links, which are efficient over long distances and give operators precise control over how much power flows. Our explainer on how the electric grid works covers the basics.
Why Canada's grids run north–south
Canada's electricity systems grew up as provincial monopolies, each planning to meet its own needs. When provinces looked for export markets, the biggest customers were often directly south — large U.S. population centres in New England, New York, the Midwest and the Pacific Northwest. As a result:
- Quebec, Manitoba and B.C. built major lines into U.S. markets to sell surplus hydro.
- Ontario is connected to Quebec, Manitoba, Michigan, New York and Minnesota.
- Alberta's links are relatively limited: connections with B.C., Saskatchewan and Montana.
- Atlantic provinces are interconnected with each other and with New England, partly through New Brunswick.
| Region | Main role in electricity trade | Key connections |
|---|---|---|
| Quebec | Large hydro exporter | Ontario, New Brunswick, New York, New England |
| Manitoba | Hydro exporter | Saskatchewan, Ontario, U.S. Midwest |
| British Columbia | Hydro; both imports and exports | Alberta, U.S. Pacific Northwest |
| Alberta | Mostly gas and renewables; limited links | B.C., Saskatchewan, Montana |
| Ontario | Large, mixed grid | Quebec, Manitoba, Michigan, New York, Minnesota |
| Maritimes | Smaller grids that depend on links | New Brunswick hub, New England |
Trade with the U.S. has generally been profitable for hydro-rich provinces, though flows can reverse. In low-water years, hydro provinces have imported more power. Trade tensions in 2025 also highlighted how much provinces rely on U.S. markets, briefly leading Ontario to impose a surcharge on some electricity exports before suspending it.
Why east–west links are getting attention
Cleaner, cheaper power
Connecting fossil-heavy grids, such as Alberta's or Saskatchewan's, to hydro-rich neighbours can reduce emissions and help integrate more wind and solar. Studies cited in federal planning suggest that expanding the Alberta–B.C. link and the Saskatchewan–Manitoba link could each produce well over a billion dollars in net benefits by 2050.
Reliability in extreme weather
Cold snaps and heat waves stress entire regions. Stronger connections let provinces help each other during emergencies. Our province guides show how each grid's mix affects its vulnerabilities.
Electrification
As homes, vehicles and industry switch to electricity, demand will grow substantially. The federal national electricity strategy released in May 2026 set a goal of roughly doubling grid capacity by 2050, and interties are a core part of that plan.
What's being planned
In 2026, federal, provincial and territorial governments identified five priority interties:
- Yukon–B.C., which would connect Yukon's isolated grid to the North American system
- Alberta–B.C., upgrading an existing link
- Alberta–Saskatchewan
- Saskatchewan–Manitoba, potentially adding up to around 2 GW of capacity along the Regina–Winnipeg corridor
- P.E.I.–New Brunswick, with new submarine cables to the Island
Other Atlantic projects, including a reliability intertie between Nova Scotia and New Brunswick, are also advancing with federal financing support. Governments have also proposed faster federal reviews, a framework for sharing costs between provinces, and expanding the Clean Electricity Investment Tax Credit to more transmission projects.
Why interties are hard to build
- Who pays? Benefits are shared across provinces, but costs often land on one utility's customers.
- Provincial priorities: Each province plans for its own reliability and may hesitate to depend on a neighbour.
- Permitting and land: Long lines cross private land, Crown land and Indigenous territories, requiring extensive consultation. Our article on Indigenous-led clean energy looks at how First Nations increasingly co-own such projects.
- Market design: Provinces with different market structures need agreements on how power is scheduled and priced.
Frequently asked questions
Does Canada have a national electricity grid?
No. Canada has separate provincial and territorial grids with varying levels of connection between them and to the U.S. Federal and provincial governments are now working to strengthen east–west links.
Do interties affect my power bill?
Indirectly. Trade revenue can help keep rates lower in exporting provinces, and imports can lower costs or improve reliability elsewhere. The cost of building new lines is recovered through rates, so the net effect depends on the project.
Can rooftop solar be shared across provinces?
Not directly. Your rooftop solar feeds your local distribution network. But as more provinces connect, surplus renewable power at the system level can flow more easily to where it's needed.
The bottom line
Interties are the bridges that let Canada's provincial grids share power, back each other up and absorb more renewables. For decades, those bridges ran mostly south to the U.S. Building stronger east–west connections is now a national priority, and while it's slow and politically complex, it's one of the most practical ways to make Canada's electricity cleaner, cheaper and more reliable.
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