Science-fiction inspired glowing energy spheres.

You can find various 1080p (Full HD) electric backgrounds on these platforms:

For a more "engineering" look, Freepik and Pngtree provide high-resolution images of circuit boards with glowing currents and digital network patterns.

Sharp, high-contrast discharges, often in blue, purple, or orange against a dark background.

Industrial shots of transformers and high-voltage wires against a blue sky. If you'd like, I can: