Steel mill I used to work for used 36 inch wide electrodes that were 20 feet long and would screw together to melt the scrap steel into a 300 ton puddle. This was called an EAF or electric arc furnace if your interested enough to look it up.
EAFs are impressive and frightening! Arcing and sparking all around. It's been years for me, but I used to help run/service onsite oxygen plants at steel mills, etc.
I remember when I was an apprentice, our class took a tour of Finkl Steel in Chicago. They had a huge carbon arc furnace they melted scrap in. They were just finishing loading it when we showed up.
The guy giving the tour said we would stay to watch the initial start up, it would be worth it. They loaded just about everything into that heat. From old engine blocks to just about any type of scrap you could think of.
When they finally cranked it up there was a loud crackling roar, and you could hear big pieces and whole engine blocks banging around inside. He told us the amount of electric it consumed, but I can't remember what it was. He did say it was so much that in the Summer they only ran it at night, because it was much more cost effective. This was back in the early 70's.
In the Summer it got so hot in the place, that the guys running the open die forging presses could go home without an excuse if the outside temperature was over 90F.