I personally find symbolic importance in Agni, the Indian god of fire found in both Vedic and modern Hinduism. It’s not just that he’s a god of fire, but the fire is important.
To me, his flames mean power, desire, and will, and in a way, he has a link to freedom. He is also seen as the spark of life itself, perhaps this might fit into energy in general. He apparently has eternal youth and immortality, probably because his fire is re-lit every day (really I’m surprised that flame ever needs to be re-lit, it’d make more sense that it be an eternal flame), thus he represents the value of youth and unquenchable spirit of life.
He also has a link with the gods Rudra (a.k.a. Shiva, my favourite god) and Indra, and interestingly both are rather energetic gods.