Light moves faster than electricity, so Kizaru would win. I honestly think Kizaru hasn't been shown to be as fast as he actually is. He's the fastest person in the One Piece world. Moving at the speed of light? That's insane. Both of them have haki as well, but there's no way anyone can react faster than lightspeed so it would be impossible to react to Kizaru's attacks. Since they are moving at the speed of light, they will also have crazy power behind them and pierce anything that he hits.