@Stryjek,
Knowing very little about what you're trying to say and whom you're addressing what you're trying to say to, I'd say keep "percentage". Percentage could potentially be replaced by "contribution" or "share" and mean pretty much the same thing, but "ratio" and "rate" would alter the meaning significantly.
A ratio compares values, so it would be "ratio of renewable energy to the overall consumed energy".
A percentage compares values to a whole, which is the
overall consumed energy?
Punkey's right about needing more but I have a feeling this is a title, subtitle, or heading of a paper? If so, my advice would be to think about what you're going to write and then decide which of your choices matches best with that.
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