I've never heard of commercial economics.  Neither has Wiki, apparently. Economists of all sorts also tend to avoid "fiat" currencies and deal in ratios instead.  It's the media that likes to report in dollars.

You're right that all the fields of energy economics have different approaches and can lead to different outcomes (especially if they are working for a particular industry).  Two things they tend to agree on is that it is complicated, changes rapidly with technology, and therefore is best handled with a carbon tax.  This way the resulting prices tend to inform people of the efficiency of each solution.

I know that carbon taxes can miss things too.  How do you price the access roads and power lines for small hydro and wind?  I did some work a while ago for a company charged for defining formulas for carbon credits.  They found that the actual benefits of technologies are highly situational, and good technologies can be put to bad use in many situations.