Last time I looked they do NOT publish power consumption. KWH per bitcoin or KWH per GHS will tell you what their product is worth.
As I recall the 5 Ghash/s unit had 30W TDP. Avalon units are 60 Ghash/s and 620W, so if long-term profitability matters (well, for BFL customers it is the last bastion of hope), they would be better compared to other solutions to date.