Energy Policy 184 (2024) 113884 Available online 21 November 2023 0301-4215/© 2023 Elsevier Ltd. All rights reserved. Solar analysis for an urban context from GIS to block-scale evaluations Francesca Vecchi a, b , Umberto Berardi a, b, * a Politecnico di Bari, Via Orabona n.4, Bari, Italy b Toronto Metropolitan University, 350 Victoria st., Toronto, Ontario, Canada A R T I C L E INFO Keywords: Solar assessment GIS Energy community Urban context Solar city ABSTRACT Global and national policies are increasingly addressing the reduction of greenhouse gases (GHG) emissions and the diffusion of renewable energy resources. Building effciency and decarbonisation pathways are often sup- ported by promoting the installation of solar energy sources. Urban solar assessments are hence extremely useful to identify favourable locations and sizing of photovoltaic (PV) installations. This research aims to estimate the solar PV potential for a city-dense context. The case study is the downtown area of Toronto (Canada). While most of previous studies look at only one scale, this work adopts a multi-scalar methodology to model PV potential within the main residential building archetypes within the selected location. Rooftop GIS-based analysis esti- mates up to 26% satisfed electricity consumption for detached houses, and 7% for apartment buildings through polycrystalline PV. A following optimisation performed with the tool URBANopt shows solar block-scale best confgurations and proftable fnancially ones. PV panels with net-metering achieve from 18% up to 41% self- suffciency. The two assessments confrm that local solar resources can reduce energy dependency on the grid and promote the feasibility of energy communities. This study demonstrates how energy tools from GIS to block- scale are critical to support local administrations in urban planning and PV plans. 1. Introduction 2. In 2021, building operation determined 27% of total energy-sector emissions and 30% of the fnal energy consumption at the global scale, mainly by the residential stock (Berardi, 2017). Regional and urban policies have progressively targeted the reduction of building energy demand while increasing local production from renewables. According to IRENA (International Renewable Energy Agency – and IRENA, 2022), considering price fuctuations, benefts from renewable production will be even more pronounced in the future as fossil fuel prices are likely to continue to rise. Renewable power is expected to continue to increase in the years ahead to reduce the impacts of fossil fuels and reach the net-zero emissions targets by policy frameworks. Renewables can contribute to satisfy the demand in urban environments, among which solar PV have the highest potential for urban micro-generation in the energy mix (Kammen and Sunter, 2016). PV is also the most feasible renewable to exploit in cities, due to scarcity of other resources (i.e, hydro or wind), space constraints, and legal restrictions (Kouhestani et al., 2019). The evaluation of feasible areas should favour roof-integrated PV technologies, being roofs the best part for solar harvesting, even more in dense cities (Kouhestani et al., 2019) (Castellanos et al., 2017). Several factors linked to roof design affect PV performance, such as surface orientation, inclination, shading, and building obstructions. Shading and obstacles mainly derive from adjacent buildings, trees, chimneys, and skylights (Odeh and Nguyen, 2021). PV systems generally operate at the back of the meter selling the overproduction to the main grid by net-metering or feed-in-tariffs (Byrd et al., 2013). Distributed solar systems contribute to decrease peak load and pressures on the power grid, improve reliability of electricity and minimise transmission-distribution energy losses due to the proximity of pro- duction and consumption points (Iazzolino et al., 2022). However, power fuctuation cause by intermittency of solar output remains a great challenge for integration to the centralised network (Manoj Kumar et al., 2020). The perspective is towards collective confgurations, which provide both energy and fnancial benefts for the users and allow en- ergy sharing. The proper adoption of PV systems in buildings requires assessment methods to establish the level of exploitation of solar energy in urban contexts and to support new territorial planning (La Gennusa et al., 2011). Several types of evaluations have been developed to estimate the solar potential on rooftops. Existing studies have widely deepened * Corresponding author. Politecnico di Bari, Via Orabona n.4, Bari, Italy. E-mail address: uberardi@torontomu.ca (U. Berardi). Contents lists available at ScienceDirect Energy Policy journal homepage: www.elsevier.com/locate/enpol https://doi.org/10.1016/j.enpol.2023.113884 Received 22 January 2023; Received in revised form 9 June 2023; Accepted 31 October 2023