Geo-referenced procedure to estimate the urban energy demand profiles towards smart energy district scenarios

Abstract

To effectively reduce cities’ environmental impact, current policies boost building stocks transition towards smart energy systems (i.e. distributed energy generation, renewables integration, energy storage, connection to district heating and cooling networks). Smart energy systems feature complex-related energy fluctuations, since they include the intermittent and unpredictable behaviour of renewable energies and the variable energy demand of buildings. However, the technical literature underlines the need for accurate methods adoptable in several urban contexts for detailed energy demand assessment. In this framework, a method to estimate the energy demand profiles of urban buildings has been developed with particular regard to the Italian contexts. The method includes a geo-referenced procedure to assess the volumetric consistency of a building stock by age, characterizing different technological solutions, and by the mostly diffuse urban use categories, i.e. residential and common tertiary (office), affecting different usage profiles, thanks to data available for the national territory. Specifically, spatial datasets on buildings from the Topographic Database, currently under standardization based on the European (INSPIRE) directive, and from the National Institution of Statistics (Istat) were used. In order to determine current hourly energy profiles, a set of dynamic energy simulations is foreseen, based on simplified reference buildings. Hence, the energy behaviour of selected building portions, representative of different heat exchanges boundary conditions, can be assessed. The derived hourly energy profiles per built volume can, therefore, be consistently associated with the considered building stock to obtain the overall hourly energy demand. Moreover, by assigning the upgraded technological properties to the reference buildings, it is possible to replicate the procedure and derive the variation of energy profiles for the defined retrofit scenario. The method has been tested on the city of Milan and is validated on a yearly basis.