Many people like the idea of a "green home." There should be many benefits, including a lower cost to operate the home.
The difficulty is there are not that many LEED certified homes, so the appraiser hasn't been able to see a trend to determine that, yes, there is a market value for that.
Unless you are selling your home, there is no reason to have the home re-appraised. Enjoy your home knowing you have done your part for the environment!