1A != 120 watts. Depends on the voltage of the drop. Some offer 208V, some offer 240V (Colostore does this). So:
1A @ 120V = 120W
1A @ 208V = 208W
1A @ 240V = 240W
And so on.
Also, 120V is pretty inefficient comparatively. Look for providers that offer 208 or 240.