Look a little closer... that large red wire is going to the battery over on the right.
The entire psu is solid 12v, so more than likely that board you see right under the sata drives takes in the 12v and converts is to a pass-through 12 and 5v for the drives.
As from the article "Power supplies convert conventional AC (alternating current--what you get from a wall socket) electricity into the DC (direct current--what you get from a battery) electricity, and typical power supplies provide computers with both 5-volt and 12-volt DC power. Google's designs supply only 12-volt power, with the necessary conversions taking place on the motherboard."
I give it a couple years and we'll soon now be seeing servers/comps with standard battery backups build directly into them like this. It would be nice as it's much more efficient than inverting 12V up to 110V only to be down converted to 12V and lower once again.
I use similar techniques on wireless sites and telecom sites I work on. Everything is standardized on either a 48V or 24V battery grid that can support the system for nearly a week without any additional power. Compared to that of perhaps an hour if it was done with traditional UPS systems. -- Justin - DSLR resident grouch and Mr Negativity TSI Fanboy - "Dontchya wish your 'net was hot like mine! Ohhh Dontchya!" Have a nice day!
The left most wires coming from the psu you see a Red,and yellow together, they go over the top of the mobo and plug into the drive.
The red and black wire goes directly to the battery. The yellow and black wires go directly to the motherboard. The tiny wires coming from the power supply go directly to the plug visibly laying on the motherboard.