well, i can tell you that it uses a total of 0 (zero) watts during hibernation... because it completely turns off... but saves everything in physical memory to a file beforehand... and next time you turn it on and boot, it loads that file back into memory so you resume from where you were.
standby leaves all the fans running, but shuts down the harddrives and most cards/peripherals... figure maybe half the power of if it was on.
[edited for typographical corrections]