Wattage depends on the power supply. USB PD gives you up to 60W. Barrel plug lets you bump the voltage (and power) up 20%. New firmware apparently let's you use

Wattage depends on the power supply. USB PD gives you up to 60W. Barrel plug lets you bump the voltage (and power) up 20%. New firmware apparently let's you use EPR, which brings you up to 124W max, but you need a EPR power supply and cable.