Emissions from residential combustion sector: How to build a high spatially resolved inventory

Usually, annual emission data from residential combustion sector are spatially disaggregated by population density to the sub-municipality spatial level. The aim of the present work is to define a methodological approach to develop/build a high-resolution emission inventory from residential combustion following a bottom-up approach. The conceptual model considers different approaches by fuel category (solid fuel-wood, gas and liquid fuels) according to distinct spatial coverage and type of activity data available for each category. For solid fuels, detailed activity data (per district), disaggregated according to the number and type of equipment, burned wood species and consumption rate, as well as specific emission factors (per wood species) were used. With regard to the gas and liquid fuels, the total national emission by fuel type using national consumption data and broader emission factors was disaggregated to the sub-municipality scale based only on the number of heating equipment. The choice of these disaggregation factors was influenced by both data availability and relevance. The results of the new disaggregated emission data have been compared with emission values resulting from the classical top-down approach using census/population data. The selected case study is Portugal. The results pointed out that major differences exist when comparing both approaches, namely regarding the spatial distribution/allocation of emissions. In the new approach, emissions are more redistributed over the territory, while in the old distribution, emissions are concentrated in the coastal urban areas (with hotspots in the main urban areas of Porto and Lisbon).