[mjevans]

I suspected it wasn't just battery farms, but more like what you see in less mass market scifi where the humans are used for more than just batteries... they'd also be some storage and processing for the system (and no longer humans).

However at that point I don't see the value of retaining the human form. It's for a story obviously, but a not-human computational device can still be made out of carbon processing units rather than silicon or semiconductors generally.