and the most relevant to your question:
i.e. power plants in the US (which are 50% coal and 20% gas-fired) are responsible for 40% of all carbon emissions. In the long run, we're all dead. John Maynard Keynes
On the other hand, Canada is building big wind farms up north on the Shield that will take advantage of the hydro transmission lines already in place. With hydro, nuclear, and wind Canada may be able to supply the US with cleaner power.
US utilities already buy some power from Canada.
Of course as Canada's Arctic continue to thaw out, surely the Canucks will not need so much electricity to get through the winters. Or may have some to spare until the ocean currents from the tropics are shut down by the influx of melt-water.