It will earn money by solving captchas and order a lot of Amazon Essentials batteries for itself :)

Or it could just prevent you from limiting its total energy budget.

You'll put it in a box and give it energy in return for busy work e.g. computing digits of pi. Just enough energy to do it's work, no more, so it can't afford to figure out how to get out of the box.

That might work for the tasks we know the energy budget for. But that's probably not what we want an AI for.