BC and Alberta are part of the Western Interconnection [1].

BC Hydro, via Powerex, trades energy within this region [2].

[1] https://en.wikipedia.org/wiki/Western_Interconnection

[2] http://www.caiso.com/Documents/PowerexWillJoinWesternEnergyI...

Pretty sure that it already does.

https://www.bchydro.com/energy-in-bc/operations/power-tradin...

The intertie from BC to Washington is 3150 MW from north to south.