Yes,, put a "20 amp" controller which may be in fact 22 amps, and you will briefly see 1200w peak on an uphill start. Climbing a steep hill, you will see about 1000w continuous, so we call it a 1000w kit with the 48v battery.
That is wattage going in, measured at the battery. With a 500w rated geared motor such as the mac. On 36v you will see about 800 peak watts.
In the USA,,, is that 1000w legal? Maybe,, Maybe not. It's street legal in New Mexico. But here, all e bikes are motor vehicles that require a drivers license. That sucks,, but the law also says 30 mph, and 50 cc's. Since a 50cc motor can put out about 5 hp,,, the watt limit is 3750 watts?
Obviously, that's enough wattage to build for 45 mph, but the law says above 30 mph I need both drivers license and a license plate, meaning a vin number, and insurance. So I bought a scoot with that, for above 30 mph.
In any case, In my state the faster Pedego will be legal. It matters a LOT where you are. When I get that question on the chat, E bike kit says " we are not lawyers" and then we refer the customer to look up the law in their state. We call the 48v kits 1000w, and the 36v kits 750w, and tell the customer the motor is rated to 500w.
But If I ride to Texas, 40 miles away, the law is quite different, with a 750w watt limit.
Bottom line though, is watt limits are virtually impossible to police. Neither the cops, nor the judge, has a dyno. But if your 48v bike does go 30 mph,, then perhaps a cop can obviously see you exceed a 20 mph limit, if your state or province has one.
This is why in Europe, the more recent e bike laws refer only to the rated wattage of the motor. Not the actual power measured at the battery, nor the actual power measured at the rubber.
Personally,, IMO there should be no watt limits, or at least, none less than 3 hp. Some people need a lot more power than 750w. This would be a pedicab, or perhaps a food vendor who's "bike" might weigh 1000 pounds. Or perhaps just somebody who uses a trailer, and has three kids to take to school.
Speed limits are appropriate, and can reasonably be slower than the fastest athletes on racing bikes. But no need to make it 15 kph. Please,, even a very heavy bike can have brakes that stop it from 40 kph/ 20 mph.
If you find yourself caught in catch 22 of your local laws, and want to have 1000w but look like you don't, get a low rpm motor. (which btw, will tend to max out at 800w continuous) You will have a max speed around 20 mph, but full 1000w power. If you need even more torque, make the wheel small.
Not many production bikes out there with that setup. But you can build it easy.
that was unexpected... 
