As I did not have the numbers fresh in memory (apparently I needed a refresh ;) ) I googled for dram data sheet and got the first ddr3 PDF (Hynix). Quick, and very dirty math suggests that

-refresh power is on the order of milliwats per Gigabyte

-memory access is on the order of 0.1W per GB per second

For refresh power, let's face it: it's puny. Regarding the active power, I have yet to see anything (off chip and this size) that is better than that.

P.S. I did say active in my original post :)