The coefficient of performance or COP (sometimes CP) of a heat pump is a ratio of heating or cooling provided to electrical energy consumed.[1][2] Higher COPs equate to lower operating costs. The COP may exceed 1, because it is a ratio of output:loss, unlike the thermal efficiency ratio of output:input energy. For complete systems, COP should include energy consumption of all auxiliaries. COP is highly dependent on operating conditions, especially absolute temperature and relative temperature between sink and system, and is often graphed or averaged against expected conditions.[3]