A basic diagram is attached which shows the design. Basically, it is a trolley, which will be moved up stairs, using conveyor belt system at its base.

I am trying to find the required power for the motor which will provide drive to the conveyor.

The conveyor's end shafts will move at 20 rpm.

Also, the torque required is given through the formula:

T = r * F

F =force component acting along the stairs = 450 N

r=dia of conveyor shaft driving pulley= 1 in= 2.54cm

So, torque comes out to be:

T = (2.54/100)(450) = 11.43 Nm

Hence, required power for motor should be:

P = T * rpm

P = (11.43)(20) = 22.86 W

Now, just by intuition, I can see that a 22W motor will nowhere near be powerful enough to drive my trolley.

What is the correct procedure which can be followed to find out the required power output from motor?