I have several friends who can on their glass-top stove. I absolutely HATE my cooktop. Hate it. But we just cannot replace it right now so I don't dare try.
Anyway, I bought that single element stand-alone electric coil for $15. It cannot be used for canning.
I had my canner on that thing for over an hour and it never boiled. I finally realized why. Even on "high," it cycles on and off.
I was able to return it. Dh looked online and there isn't a single, stand-alone electric coil that is capable of canning.
So, FYI, if anyone is looking for one, get propane.
But, I remembered
that I have a small electric (coil) stove in my kids' room (we have a MIL suite above our garage and that's where they sleep). So, that's become my canning kitchen. I canned my marionberry jam up there and it turned out!