The conversion of energy during electroplating
That's a good start, but there is also ohmic loss, as much of the energy is also converted to heat in the electrolyte, electrodes or even wiring.

BTW, during WWII, silver was used to replace copper bus-bars in stationary machinery such as electrolysis apparatus, freeing the copper for use in war materiel and slightly improving the efficiency of the apparatus due to its better conductivity then commercial copper.