G5 pumps up too much?

According to Apple, the G5 is a success from an energy savings standpoint and it consumes only 2W in deep sleep.
But on the Apple Forums, measures show that in fact, it consumes about 40 W. Worse, shutdown, it still eats more than 30W!
One may wonder where goes that energy which could power a Mac mini under full CPU load.
If you have the equipment to measure accurately how much your Mac consumes, please send us your results.