Comparative life cycle assessment of electric and gas ovens in the Italian context: An environmental and technical evaluation

This paper aims to analyse and compare the environmental and technical performances of two domestic oven technologies (one powered by natural gas and one by electric energy) considering the Italian context, such as Italian social and food habits. These household appliances are subject to energy labelling and are the most diffused cooking systems along with hobs. This study was performed in accordance with the international standards ISO 14040/14044 and adopted the attributional LCA approach. The analysis is related to the functional unit "the baking of food, considering the Italian context and a lifetime of 10 years". The analysis includes all phases of the life cycle except for maintenance and transport, which were considered negligible for this analysis. The materials and manufacturing phases necessary for the production of the two ovens were considered in the analysis, and the data were provided by the ovens' manufacturers. The products' use phase was considered through the measurement of resources (both natural gas and electric energy) consumed during the cooking simulation by experimental tests that simulated a heating cycle of a standard load represented by a brick. The product end-of-life phase was considered in accordance with the current regulations and statistical data in this sector. The Ecolnvent database was used as a reference for background data. The ReCiPe life cycle impact assessment method was used for the assessment of the environmental impact categories. This study shows the dominance, in terms of the environmental impact, of the electric oven with respect to the gas oven in every indicator considered in the analysis. In particular, the electric oven accounts has an approx. 3 times greater impact than the gas oven on the climate change, freshwater ecotoxicity and marine ecotoxicity impact categories, while for the ozone depletion, fossil depletion metal depletion and natural land transformation categories, the results are similar, with a slight dominance of the electric oven (approx. 2-5%). This finding is related to the use phase and results from the different energy carriers used and the time required for cooking in the two cases. Indeed, the nature of the energy carrier for the electric oven and the time required for cooking (based on the energy efficiency test) is longer compared to those of the gas oven. This result, which is clearly in favour of the gas oven in the Italian context, leads to the conclusion that the main contribution to the environmental load of the electric oven is the Italian electricity grid mix, which is mainly based on non-renewable sources. Therefore, this analysis depends on the geographic area of interest, and the results can significantly change if different contexts are analysed. (C) 2019 Elsevier Ltd. All rights reserved.