Here is an interesting read about the average power consumption of an avatar per anno (German only).
When you take in count the about 4000 servers used for running the grid, the computers used to control the avatars and coolant systems in the data center of LL one avatar consumed about ca. 1752 KWh per anno. The average power consumption of an inhabitant from Brazil seems to be 1884 KWh.
So what should we do with these measures? Nick at them, it is an interesting number, but meaningless all the way for all other except LL, who has to pay the energy bill for its datacenters.