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UK Grid: Live+ How the Americas' grids interconnect

How the grids of the Americas connect to each other

North and South America aren't wired together into one continent-spanning grid, and even within each continent, power doesn't flow freely everywhere. The USA, Canada and Mexico run three separate synchronous interconnections, tied together only by a handful of HVDC back-to-back stations. South America is looser still: mostly bilateral ties between neighbours, several of them built around specific shared hydroelectric dams rather than a general-purpose grid link. This page maps out which grids actually connect to which, and how much power those connections can actually carry.

North America: three interconnections, tied together by HVDC

Within each interconnection below, every generator runs locked to the same AC frequency and power flows freely. Between interconnections, power can only cross via HVDC back-to-back ties, which convert to direct current and back rather than letting the two sides run in sync.

Western Interconnection US West, British Columbia, Alberta Eastern Interconnection US East, Ontario, Manitoba, the Maritimes Québec asynchronous - HVDC only ERCOT Texas - islanded by design Mexico (CENACE) Sistema Eléctrico Nacional ~1,320MW combined 7 back-to-back DC ties 820MW combined 2 DC ties ~2,170-2,275MW HVDC Radisson-Sandy Pond, Highgate, Appalaches-Maine small AC/HVDC ties

Schematic only - not to scale and not a geographic map. Line thickness doesn't reflect capacity.

  • Eastern Interconnection - covers most of the US east of the Rockies, plus Ontario, Manitoba and the Maritime provinces of Canada. IESO's Ontario grid, covered on this site's Canada page, sits inside this interconnection.
  • Western Interconnection - covers the western US, British Columbia, Alberta and a sliver of northern Mexico (Baja California).
  • ERCOT (Texas) - covers most of Texas, deliberately kept separate from the other two (and largely outside US federal FERC jurisdiction) specifically to avoid interstate power flows. It ties to the Eastern Interconnection via two back-to-back HVDC stations totalling 820MW: a 220MW North tie at Oklaunion and a 600MW East tie between Monticello and Welsh.
  • Québec - nominally part of the Eastern Interconnection's synchronous area geographically, but Hydro-Québec operates it asynchronously, tied to its neighbours only via HVDC - largely a historical/operational choice rather than a geographic necessity. Its ties to New England alone total roughly 2,170MW of import and 2,275MW of export capacity across several lines, including the Radisson-Sandy Pond multiterminal HVDC line (regularly carrying 1,200-1,400MW+), the older 225MW Highgate interconnection, and the newer Appalaches-Maine line (adding a further 1,200MW).
  • Eastern-Western tie - seven back-to-back HVDC converter stations strung along the Great Plains (Rapid City SD, two in the Nebraska panhandle, Blackwater and Artesia NM, Lamar CO, and others), carrying roughly 1,320MW combined.
  • Mexico - the Sistema Eléctrico Nacional, operated by CENACE, connects to the US Western and Eastern Interconnections via several smaller HVDC and AC ties near the border, and is not otherwise synchronised with either.

South America: bilateral ties, often built around shared dams

South America has no single transparency platform or synchronous supergrid the way Europe or North America do. Most cross-border links are bilateral, and several of the largest were built to share output from a specific hydroelectric dam sitting on a border river, rather than as general-purpose interconnectors.

Colombia Venezuela Ecuador Brazil Paraguay Argentina Uruguay Chile 450MW 290MW (reactivating) Itaipu - 14,000MW Yacyretá - 3,200MW Garabí - 2,200MW Salto Grande - 1,890MW 500MW Andes-Cobos - up to 200MW currently disconnected

Schematic only - not to scale and not a geographic map. Line thickness doesn't reflect capacity, except Itaipu is drawn heavier as by far the largest tie shown.

  • Itaipu Dam (Brazil-Paraguay) - 14,000MW installed across 20 generating units, making it one of the largest hydroelectric plants ever built. It's jointly owned and operated by Brazil and Paraguay; Paraguay uses only a fraction of its half of the output domestically and exports the rest to Brazil, making Itaipu a huge, permanent cross-border flow rather than an occasional trade. Ten of its units generate at 50Hz (Paraguay's frequency) and ten at 60Hz (Brazil's) - the output is converted between the two.
  • Yacyretá Dam (Argentina-Paraguay) - 3,200MW installed, a second large jointly-operated hydro dam on the Paraná river, supplying around 60% of Argentina's hydroelectric output.
  • Garabí (Argentina-Brazil) - a 2,200MW back-to-back HVDC station (two 1,100MW phases), rather than a shared dam - it converts power to DC and back specifically because Argentina and Brazil's grids aren't frequency-synchronised.
  • Salto Grande (Argentina-Uruguay) - 1,890MW installed, a shared dam on the Uruguay River, plus a separate roughly 500MW AC interconnection directly between Brazil and Uruguay.
  • Chile-Argentina - the Andes-Cobos line carries up to 200MW from Argentina to Chile (80MW the other way), but has been disconnected from Chile's national grid in recent years - reflecting how these ties have historically been used more for emergency backup and limited exchange than large sustained commercial flows.
  • Colombia-Ecuador - 450MW combined across two lines (a 230kV double circuit and a smaller 138kV line).
  • Colombia-Venezuela - two lines totalling 290MW, historically underused and largely inactive through the 2010s and early 2020s amid Venezuela's own grid reliability problems; both countries announced steps to reactivate and expand the link in 2026.

There's no single South American equivalent of ENTSO-E's transparency platform - actual traded volumes across each of these ties would need querying from each country's own operator individually, which this site doesn't currently do. See each country's own page in the South America overview for what live data this site does and doesn't have.

Tie capacities compared

The figures above, ranked by installed/rated capacity - Itaipu alone is roughly the same size as three or four of Great Britain's largest power stations combined.

Figures are installed/rated capacity of each tie or dam, not typical actual flow, which is usually well below the rated maximum. See sources below for each figure. Last checked: 23 August 2026.

Sources

None of the grids on this page or on this site's other Americas pages are electrically connected to Great Britain - they're tracked here purely so their figures can be compared against GB's and against each other on the Comparisons page.