Towards productive cities: environmental assessment of the Food-Energy-Water nexus of the urban roof mosaic

Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the...

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Detalles Bibliográficos
Autores: Toboso, Susana, Nadal, Ana, Petit, Ana, Pons Valladares, Oriol|||0000-0003-1747-8150, Villalba, Gara, Gabarrell, Xavier, Josa Garcia-Tornel, Alejandro|||0000-0003-1180-7910, Rieradevall, Joan
Tipo de recurso: artículo
Fecha de publicación:2018
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/125341
Acceso en línea:https://hdl.handle.net/2117/125341
https://dx.doi.org/10.1111/jiec.12829
Access Level:acceso abierto
Palabra clave:Green roofs (Gardening)
Urban agriculture
Solar energy
Industrial ecology
Life cycle assessment (LCA)
Rainwater harvesting
Resource self-sufficiency
Cobertes verdes
Agricultura urbana
Energia solar
Àrees temàtiques de la UPC::Edificació::Construcció sostenible
Àrees temàtiques de la UPC::Energies::Energia solar fotovoltaica
Àrees temàtiques de la UPC::Edificació::Elements constructius d'edificis::Elements de tancament
Descripción
Sumario:Cities are rapidly growing and need to look for ways to optimize resource consumption. Metropolises are especially vulnerable in three main systems, often referred to as the FEW (i.e., food, energy, and water) nexus. In this context, urban rooftops are underutilized areas that might be used for the production of these resources. We developed the Roof Mosaic approach, which combines life cycle assessment with two rooftop guidelines, to analyze the technical feasibility and environmental implications of producing food and energy, and harvesting rainwater on rooftops through different combinations at different scales. To illustrate, we apply the Roof Mosaic approach to a densely populated neighborhood in a Mediterranean city. The building-scale results show that integrating rainwater harvesting and food production would avoid relatively insignificant emissions (13.9–18.6 kg CO2 eq/inhabitant/year) in the use stage, but their construction would have low environmental impacts. In contrast, the application of energy systems (photovoltaic or solar thermal systems) combined with rainwater harvesting could potentially avoid higher CO2 eq emissions (177–196 kg CO2 eq/inhabitant/year) but generate higher environmental burdens in the construction phase. When applied at the neighborhood scale, the approach can be optimized to meet between 7% and 50% of FEW demands and avoid up to 157 tons CO2 eq/year. This approach is a useful guide to optimize the FEW nexus providing a range of options for the exploitation of rooftops at the local scale, which can aid cities in becoming self-sufficient, optimizing resources, and reducing CO2 eq emissions.