COP is a measure of efficiency a ratio of Output energy/Input energy. Thus if 2 kW electric input can give 4 kW of energy output then the COP=2
Google this:- Can coefficient of performance be less than 1? Google answer is
"Thus, we can say that the COP of the refrigerator and air-conditioner can be less than one or greater than one. The above formula also shows that the COP of the heat pump can never be less than one; it is always more than one."
I am not sure this final statement is correct because if you are driving the fridge compressor outside the heated room then all the friction power is lost into the atmosphere and not into the refrigerant. So if the heat source is more than say 10 degree.C less than the room temperature inside you could be loosing energy rather than saving it?
