Energy discharging around wharf, making a racket (3-8)

I haven't cracked this one yet — but the brilliant team at Fifteensquared have:

E (energy) + ARCING (discharging) round PIER (wharf) (It took me a long time to think of looking up the unlikely-looking ARCING, which I couldn’t explain: ‘Arcing is a type of electrical discharge that occurs when electrons flow between two conductors, usually metal, in an environment with a gas or vacuum. The conductors can be wires, rods, or other objects that are capable of carrying an electrical current.’)