hi Nilanka.Costa
There is currently no such option in the controller, you could use some sort of script to log in and turn off the VAPs during the night, but I have never seen anyone actually perform any analysis of the power saved. Mind you, If you were going to automate the turn on/off of vaps, you may as well connect to the edge switch and turn off the POE directly to achieve a full shut down.
regards
-jeff