Is it a 240V or 120V outlet? What amperage is it wired for? Check your breaker box to see the amperage for the circuit breaker if needed.
I'd go 5500kw if you've got access to 240V, but it also depends on what else you plan on running along side the element. If you've got 120V outlets, all electric won't cut it. You would be able to bring things to strike and sparge temps depending on the vessel (would take something like 90 minutes though), but I don't think you'd be able to biol.