In this task, you are given a paragraph, and your job is to generate comma-separated entities present in the given paragraph. Generate entities from a given passage in such a way that (i) they are present in the paragraph, (ii) they are non-duplicate, (iii) they underwent a state change during the process. Avoid creating entities that (i) aren't present in the process paragraph and (ii) aren't significant.

The coal is placed in a heater. The coal is super heated. The heat is connected to a boiler. The boiler is full of water. The heat turns the water into steam. The steam turns a generator. The generator produces the electricity.
coal ,heat ,water ,steam ,generator ,electricity