You can work out an approximation based on percentage components and the energy cost to liquify air. Assume that the energy comes from electricity and you can derive your figures.
This gives you a first approximation. However it gets messier than that, as in cleverly designed plants, you can recover much of the energy used by using the chill to precool the next batch of air.
The actual energy cost should be the same as that of making liquid nitrogen or liquid oxygen. As a very crude estimate about the same as to evaporate an equal mass of water.
As a side issue, most argon windows do not keep their argon for more than 5 years. Using the solar gain simulator on Lawrence Livermore's website, I found that in my climate (northern Alberta 10,000 degree heating days per year) that a south facing double glazed window was more efficient than a triple glazed window. You lost more heating from sunlight than you gained by it insulating better.
In terms of energy, a better strategy for a heating climate is to have your windows on the south side, token windows on east and west, and closets, bathrooms, and mechanical spaces on the north side. South facing windows should have adjustable awnings to shade them when desired when not in the heating season.
The price differential of argon triple pane windows will pay for a good set of insulating window covers.
