netbsdnoob Start with the "hogs" first: estd for CPU throttling; xset dpms to power the screen off; atactl/scsictl for the (spinning) HDD.
You could also try "suspending" unused devices (beware: may not work at all/could uncover kernel bugs...). Get a device list using drvctl -l -t, then use -S.
I used to use this script, but now I just compile a custom kernel:
$ cat ~/bin/disable-devices.sh
#!/bin/sh
sudo wsmuxctl -f 0 -r wsmouse0
for d in pms0 ubt0 uvideo0 uts0
do drvctl -S $d
done
$
However, disabling stuff in BIOS is a much better option.
