I would think has decent application within apartment buildings, as they are valued via cap rates. Most all have some sort of common electric: exterior lights, laundry facilities, heating pools, clubhouses, etc. How much common power costs do you lose a year. On an 8% cap rate and assuming you get the same deal as the coop above was able to pull, your break even is $8k/year. I would think most large complexes pay at least that much a quarter.

Hell, you might be able to get an even better deal if you offer them publicity as going green.

SteveO or Gaston - you ever look into this?

RealOG