Renewables are ways of making power that can keep coming — sun, wind, moving water, heat from the earth. People also use the word for that power as a group: “We need more renewables.” Though actually, the careful name is renewable energy; renewables is the short plural you hear in news and politics. We almost never say “a renewable” the way we say “a tree.” The idea is that the source does not get used up in one go: the sun will rise again. Coal and oil are the opposite. People stretch the word: some count wood or plant fuel as renewables, even though trees take years to grow back, and not everyone agrees that is clean. It is a public, school-and-news word, not a poetic one.