Originally Posted by wilserbrewer
IME a 2000w element will hold a boil for 5 gallon batches FWIW.
I will second that, If you don't mind waiting a little bit a single 2000W element is all you need for a 5 gallon batch. so long as you don't have a gigantic kettle with lots surface area to loose heat, it helps to insulate as well.
I have biab set up with one 2000 W element in a 11 gallon pot and it takes about 35 min to go from mash out to boil on 6.5 gallons if i put the lid on and wrap the kettle in a blanket.