Sustainable heating fuels and technologies for households not connected to natural gas grid in Po valley, Italy

Po Valley in Italy is characterized by severe air pollution problems in terms of particulate matter (PM) and nitrogen oxides (NOx). The study focuses on small mountain municipalities in this territory that are not connected to the natural gas grid and F-climate zones that are eligible for liquefied petroleum gas (LPG) subsidies. The sustainability of the main two residential heating fuel alternatives in the area (i.e., biomass and LPG) is investigated in terms of primary PM and NOx emissions by studying two emission reductions scenarios where the heating demand currently provided by solid biomass combustion is hypothesized to be covered with advanced wood pellet appliances or by LPG. The associated equivalent CO2 emissions are also calculated. The study concluded that the turnover of biomass appliances reduces significantly the PM emissions but may not be an effective way to reduce NOx emissions in the area. Gaseous fuel (e.g., LPG) combustion may bring more benefits in this respect. Both wood pellets and LPG cause fossil CO2 emissions to some extent.