You can disconnect from the grid but just like having a lawyer on retainer cost something so does having the power company on retainer.

It's why cloud servers cost so much more than your own on-prem solution, and on-demand offices more than your own.

And if you want an engineer on call it's gonna cost you. If you work in software, think about it, how much would you charge for a job where they could call you anytime and expect you to start work.