Energy and environmental impact of domestic heating in Italy: Evaluation of national NOx emissions

The domestic heating sector has a high potential in terms of energy savings and environmental impact. In the present study, an analysis has been carried out on the effect of domestic heating on natural gas (NG) consumption and pollutants emissions. In particular, among various emission pollutants, the nitrogen oxides (NOx) emissions at national level were analyzed in detail. The work was carried out under a collaborative research project between the Italian Ministry of the Environment and Politecnico di Milano. For the assessment of the national NOx emissions due to residential heating, an inventory of the domestic boilers stock operating in Italy from 1999 to 2010 was made. As from a technological point of view, the precise data about the real composition of national domestic boilers stock were incomplete and not updated, a methodological procedure was developed in order to reconstruct the national domestic boilers stock based on the available technologies and thermal power. According to this scenario, the technological improvement of national boilers stock in the last decade was evaluated in terms of natural gas saving and reduced NOx emissions. Further some discussion has been made on the energy policies for the diffusion of more efficient boilers. ► First-of-its-kind study on the effect of domestic heating on NOx emissions. ► Inventory of national gas boiler population for domestic heating. ► Estimation of the main boilers typologies distribution on a national level. ► Technological improvement of thermal appliances and NOx emissions reduction.