I have a steam powered tea pot let me explain
It's one of those translucent plastic cylinders molded with a tight fitting lid that has two spouts: one with a square opening and another with a grate that doesn't filter small things like broken leaf tea.
Hot tea in this tea pot contains water with a high vapor pressure, one that is high enough to evaporate enough water to create a pressure large enough to lift the lid. The pressure inside and out was atmospheric pressure until water began evaporating from the tea I put in the tea pot.
The lid doesn't lift very far, but the bearing surface is tea, so the friction is low enough for the lid to move up.
Or conversely there is a small passage, albeit larger than all the rest, through which I can hear bubbles popping as the evaporated water leaves the tea pot. What was initially a flat interface between the membrane of tea and the external atmosphere was pushed out by this pressure difference. The push was the water vapor and air pushing against the surface tension of the tea membrane. It takes force to deform a fluid membrane.
So my steam powered tea pot is running on the heat energy in the hot tea inside it. The work it is doing could be lifting the lid but it surely is popping water bubbles that I can hear.
