Abstract: A side wall for a UHP electric arc furnace includes water cooled panels positioned within the outer shell of the furnace. The panels form water channels and have multiple fins projecting inwardly from the panel into the furnace. The panels including the fins are formed of pure copper or copper alloy which has a high heat conductivity. The fins have a thickness of at least 10 mm and they project horizontally inwardly toward the furnace for at least 70 mm. The fins are spaced vertically apart in the range of 30-80 mm. The space between the fins is filled with a castable refractory.