Hi @lorenzobc 
,
tlp recently conflicts with power-profiles-daemon. You can only have one or the other. Check this: tlp-rdw and power-profiles-daemon are in conflict / Pacman & Package Upgrade Issues / Arch Linux Forums
You can remove one of those and install the other. For example
sudo pacman -Rdd tlp # Since it is part of the cosmic package
sudo pacman -S power-profiles-daemon