Plasmatic energy is a type of energy associated with some subspace phenomena, including sporocystian lifeforms such as the Nacene.
In 2372, the formation of a plasmatic energy field in main engineering aboard the USS Voyager preceded the appearance of Suspiria. (VOY: "Cold Fire")
Plasmatic energy discharges are associated with astral eddies, such as those encountered by Voyager in 2373. (VOY: "Real Life")