The influence of the type of energy sources and their share in the local energy mix associated with the generation of electricity in the local energy market is important for the energy efficiency evaluation of heat pumps. At the final energy level the changes of energy effectiveness of the heat pump depend on the working mode and external operating conditions. Therefore, the variability of the external conditions is assessed by defining the values of the seasonal coefficient of performance or the seasonal energy efficiency ratio for the analyzed working mode. These indicators of the effectiveness are not sufficient to assess the full impact of the heat pumps on the environment. To determine this impact, an assessment based on the methodology of primary energy use is proposed. Based on the primary energy evaluation, the greenhouse gases emission (CO2) into the environment is assessed. To determine the impact of hazardous emission on the environment, the emission conversion factors are used. The values of these factors incorporate the conversion of primary energy with respect to the types of fuels and thermal power plants in the local energy market. The results of applying this method to the heat pump (HP) with the air as the lower heat source powered by electricity produced locally in the system of photovoltaic panels (PV) or electricity taken from the grid are reported. The gas boiler has been assumed as a peak source of heat. For the simulation of the HP and PV operation, real hour-by-hour data on solar radiation and ambient temperature have been used.