Automatically restart Windows with Boot Camp on Mac after a power failure
You can set your Mac to always restart after a power failure. You might want to do this if you need to access your Mac remotely or it performs other functions for you when you’re not around.
You can set power options if your computer does not have a built-in battery. Portable computers such as the MacBook Pro and MacBook Air have built-in batteries.
In Windows on your Mac, click
in the right side of the taskbar, click the Boot Camp icon 
, then choose Boot Camp Control Panel.If a User Account Control dialog appears, click Yes.
Click Power.
Select “Restart automatically after a power failure.”