An electrostatic charge was an energy discharge that was typically associated with the result of phaser energy, a transporter beam or a force field. The Hur'q, after absconding with the mythical Sword of Kahless from Qo'noS in the 14th century, placed it behind a holographic wall with a force field emitting an electrostatic charge. It was not discovered until 2372. (DS9: "The Sword of Kahless")