You can save lots of energy and manual intervention by adding an option to shut down the device after the operation is completed.
Few places we can have this option is.
1. Copying of files - Give a checkbox that says "Shut down after copy"
2. Downloading of files. - Give a checkbox that says "Shut down after download"
Also in shut down, direct options like Shut down after 1 or 2 or 3 hours, should also help.
Often before leaving the desk, we either need to cancel or wait for some action to finish. In all such places, we can have this option.