Contrary to belief, they are low amp usage. Been using a single burner unit in our Landmark for the last 3 1/2 months. Wife loves it!! Keeps the moisture down, cooks quicker and more efficiently. Has not once tripped the breaker it is on with a space heater. But beware, when we bought one for the house, it did require us to buy all new "MAGNETIC" cookware!!!!
Yeah, I went around and tested my good hard anodized aluminum cookware with a magnet - no stickee!! They make an adapter plate for about $35 that is steel and heats up from the induction current, and you can put ANY cookware on top of that. Right now, the shipping charges on the TV offer cooktop sets kills that. Some reasonably priced other brands on WalMart.com and Amazon, with high user ratings.
The highest wattage standard cooktop is 1800 watts on full power, and works on a normal 15 amp AC circuit. There are some bigger "commercial grade" ones out there, and they cost a lot of bucks.
Edit: Although a magnet won't stick to my cookware, it carries the "Induction Compatible" symbol on the bottom - sort of a spiral.
I can always use my black iron frypan and grillpan with the induction cooktop.