The Galactic Empire utilized the Capacitor, a mobile structure located at a concealed facility within a volcano on the planet of Sullust. This installation harnessed geothermal power, gathered by twelve transmitters embedded in the volcano's base, to generate a protective shield. During the Raid on Sullust, Rogue Squadron, a Rebel flight group, deactivated the shield by eliminating all the transmitters, then they collapsed the Capacitor by targeting its central support structures.
The video game Star Wars: Rogue Squadron, released in 1998, features the Capacitor.