Western Interconnection
The Western Interconnection is an electrically connected grid spanning the western United States, parts of Canada and northern Baja California. Explore its map, compare demand for its US portion and open the individual markets within the system.
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Markets and their latest readings
| Market | Price | Load | Updated | |
|---|---|---|---|---|
| Eastern Interconnection | ||||
| SPP | ||||
| Western Interconnection | ||||
| CAISO | ||||
| BPA | ||||
| Baja California | ||||
| AESO | ||||
What is the Western Interconnection?
Where is the Western Interconnection?
The Western Interconnection spans the western United States, parts of Canada and northern Baja California. Its electrical footprint crosses state and national borders. The map shows transmission and balancing-area geography, while each demand figure and market reading names the geography it measures.
Western Interconnection electricity markets
CAISO and the Bonneville Power Administration operate within the Western system, alongside other utility balancing areas. SPP also operates a western balancing area. Their separate operating footprints and prices are retained in the market board.
How it connects to other power grids
Systems within an interconnection operate synchronously. Transfers across the seams between interconnections use specific connecting facilities and are constrained by their capabilities. A large demand total alone does not establish how much electricity can be moved across a seam.
Western Interconnection demand
The demand comparison uses the US portion at a common EIA hour, including authorities outside organized markets. Canadian and Mexican readings retain their separate scopes in the market board. Reporting coverage and reconciliation determine whether the US Eastern and Western totals can be compared.
Questions
What does the Western Interconnection include?
It connects the western United States, parts of Canada and northern Baja California. Its balancing authorities and market operators coordinate their own areas within that connected system.
Is the Western Interconnection one electricity market?
No. It includes multiple market operators and utility balancing areas. Their prices, rules and reporting times remain distinct.
Does this demand total include Canada?
The EIA demand total covers the US portion only. Canadian market readings appear separately, with their own timestamps.
Can I compare Eastern and Western Interconnection demand?
The US demand comparison uses the same EIA hour for both. A ratio is supported only when the required coverage, reconciliation and freshness checks pass.