Now that's an interesting take :-) Distributing said energy to cells would be non-trivial, and you'd still need nutrients. Also humans need rest and unlike ma

Now that's an interesting take :-) Distributing said energy to cells would be non-trivial, and you'd still need nutrients. Also humans need rest and unlike machines, the range of environmental conditions in which they can rest is narrower than their operational conditions (all of which are rather narrow and non-existent beyond the biosphere). Also, you can't suspend or reboot humans. Once they crash, they must be recycled.