The present paper investigates possible primary energy savings deriving from the utilization of air to air heat pumps for building heating purposes.
The energy input of heat pumps is generally represented by electricity and, in the last years, the share of renewables on the total electricity generation has grown in all the industrialized world, therefore the average carbon emission factor has decreased.
According to this scenario, heat pumps maybe conveniently employed for heating purposes in the residential sector to support its de-carbonization through the substitution of natural gas boilers.
The impact of the heat pump utilization is analyzed by implementing a simplified end-use energy model. The model is based on the definition of the Carnot efficiency of an inverse cycle, which permits to estimate the performance of a heat pump in a direct and simple way according to the indoor and outdoor temperature of the location of installation. Then, a simple methodology is introduced to obtain an estimation of territorial energy consumption, so that different scenarios can be analyzed and planning or policy evaluations can be proposed.
Finally, a case of study is considered to show the practical application of the proposed method.