she could, but she doesn't absorb energy constantly. she can turn it off.
now that I think about it.......Carol's absorber powers haven't really been explored. we know she can absord electricity and heat.......but that means she can also absorb light. It's all EM radiation. So, she could create a small zone of absolute darkness and cold. To hide in, maybe?
Plus......ya know what else uses electricity? nerves. could she suck the electricity right out of someone's neurons? what if she learned neurobiology, practiced a lot, and learned to recognize patterns in people's brains -- a.k.a. thoughts? could she consume someone's mind? Now that I think of it, she already did that to Monica once. voluntarily, of course. And Monica was still aware inside Carol's mind....
She would make one hell of a villain if she took that route. going around consuming people's minds, keeping them prisoner within her own, extracting information from her "prisoners". what would her mind be like after she ate a hundred people? a thousand? a million? Would she even be remotely sane? would her brain be a constant battleground as millions of consumed minds fought for control of her body? I guess to everyone else she'd just look like a schozophrenic with epilepsy.
Carol the soul-eater. I like it.