A computational workflow for urban micro-simulation of buildings' energy performance

The micro-simulation of buildings’ energy performance at the urban scale en- tails the dynamic simulation of buildings’ energy demands in a spatially resolved way; and of the supply of energy to meet these demands. Two approaches have emerged to meet the increasingly important need for such simulations: repeated calls to detailed dynamic simulation software that was designed for simulating single buildings, or a single call to simplified dynamic simulation software that was designed for simulating arbitrary numbers of buildings simultaneously. In this paper we describe a workflow that is under development to support application of the latter approach at multiple scales, ranging from single buildings, through neighborhoods, to districts and whole cities. This approach is based on CitySim, which remains to our knowledge the most comprehensive dedicated urban energy micro-simulation software. This workflow focuses on the utilisation by CitySim of an emerging standard for the semantic attribution of 3D urban models called CityGML, the import and export of CityGML files from a 3D database called 3DCityDB, methods for the population of this database, and on the generalisation of CitySim to solve for scenes of different spatial extent and level of detail. This paper describes this new workflow and its potential application to the simulation of urban scenes of varying complexity, from a simple street canyon to an urban district. This workflow is to represents our first step in the development of an integrated urban modelling platform for the simulation of physical resource flows and the socioeconomic phenomena that influence them. We close this paper by discussing the challenges that await us in the development of such a comprehensive urban modelling platform; challenges that range from the preparation of data, interoperability through the exchange of data for scenes of contrasting scale, the orchestration of services utilising this data and the visualisation of resultant output data

Local public utilities in Grenoble and Metz : partially appropriate urban energy tools

L'action publique comme la recherche développent un intérêt croissant pour les relations entre ville et énergie. Cette thèse porte sur la manière dont les opérateurs énergétiques de réseaux participent à l'élaboration et à la mise en œuvre de politiques énergétiques locales et sur la capacité des acteurs politiques urbains à les piloter en ce sens. La question est abordée à partir d'acteurs alternatifs de la distribution d'énergie en France, les entreprises locales de distribution (ELD). Celles-ci assurent depuis plus de cent ans la distribution et la fourniture d'électricité et parfois de gaz et de chaleur dans les territoires de communes qui les possèdent. Elles apparaissent aujourd'hui comme des leviers d'action innovants à la disposition des villes pour développer des politiques énergétiques urbaines. Centrée sur les opérateurs urbains, la thèse examine les situations de GEG à Grenoble et d'UEM à Metz. Malgré leur implantation locale, les ELD accordent depuis quelques années seulement une place importante à l'échelle urbaine dans leurs stratégies d'entreprises. L'organisation sectorielle et centralisée du service public de l'électricité a pendant longtemps happé les ELD, freinant l'émergence d'une approche spécifique de leurs territoires de concession. Les recompositions du modèle économique qu'impose la libéralisation amènent toutefois les ELD à rechercher de nouveaux relais de croissance. Se saisissant d'opportunités liées à la mise à l'agenda de politiques énergie-climat, elles font preuve d'une forte adaptabilité et élaborent de nouvelles stratégies valorisant davantage leur ancrage urbain. Longtemps dominées par des logiques sectorielles d'ordre national, les entreprises locales participent ainsi de plus en plus au développement d'actions énergétiques urbaines. Cet ancrage urbain ne fait pas pour autant des ELD des outils de gouvernement d'une politique énergétique urbaine, qui supposerait une capacité d'initiative et de pilotage des acteurs politiques municipaux en fonction d'objectifs propres. Par l'analyse des exemples de Grenoble et Metz, nous montrons que la construction de l'énergie comme enjeu politique local est à la fois progressive et hétérogène, remettant en cause une approche jusque-là essentiellement économique et industrielle du pilotage des ELD. La politisation en cours se heurte cependant à une expertise limitée des communes sur l'énergie, qui ne parviennent que très imparfaitement à intégrer leurs préoccupations énergético-climatiques dans le pilotage stratégique de leurs entreprises locales. Les changements sont en revanche beaucoup plus importants sur le plan opérationnel, dans des projets qui impliquent des relations partenariales autour d'enjeux énergétiques : plans climat-énergie territoriaux, réponses à appels d'offres nationaux et européens, coordination des réseaux de distribution…L'analyse du modèle énergétique territorial alternatif des ELD proposée dans la thèse montre que le statut local des opérateurs ne suffit pas au développement d'un gouvernement énergétique urbain, lequel procède aussi de la politisation des questions énergétiques et de la construction d'une expertise adaptée au sein des systèmes politico-administratifs urbainsPublic action, like research, is becoming increasingly interested in the relationship between cities and energy. This thesis focuses on the ways in which energy network operators participate in the development and implementation of local energy policies and in the capacity of urban political stakeholders to drive these operators in this sense. The question is approached through local public utilities (LPU) as alternative energy distribution stakeholders in France. These companies have ensured supply and distribution of electricity and sometimes gas and heat in the areas where they are present for over one hundred years. They appear today to be innovative levers to action available to cities to develop urban energy policies. Centred on urban operators, this thesis examines the cases of GEG in Grenoble and UEM in Metz. Despite their local roots, LPUs have only in recent years granted an important place in their business strategies to the urban scale. The sectoral and centralised organisation of the electricity public services have for a long time limited the capacities of the LPUs, impeding the emergence of approaches specific to their particular areas. Reconfigurations of the economic model which impose liberalisation cause the ELDs to constantly search for new growth sources. Seizing opportunities from emerging energy-climate policies, they are proving their great adaptability and have devised new strategies valorising to a greater extent their urban roots. These urban roots alone are not enough to make the LPUs governmental tools for urban energy policy, which supposes a capacity for initiative and control by the political stakeholders of their own objectives. Through analysis of the Grenoble and Metz examples, we demonstrate that presenting energy as a local political issue is both progressive and heterogeneous, calling into question an approach to LPU control which until now has been essentially economic and industrial. Politicisation is being hindered by the lack of energy expertise in the communes, which only very infrequently manage to integrate their energy-climate concerns into strategic plans for their local businesses. In contrast, changes in operational plans are much greater in projects which involve partnerships around energy issues: regional climate-energy plans, responses to national and European calls for public tenders, coordination of distribution networks…The analysis of an alternative regional energy model from the LPUs proposed in this thesis demonstrates that the local status of operators is insufficient for the development of urban energy governance, which also operates in the politicisation of energy issues and the development of specially adapted expertise within urban political and administrative system

Grounding urban energy tools in the lived experiences of the urban poor - a case for incorporating participatory methods in urban building energy models

Abstract Urban building energy models (UBEMs) are an example of a data-driven method for predicting energy consumption and assessing the impacts of policies aimed at reducing carbon emissions in cities. Such tools are gaining increasing ground as cities and governments seek to understand and manage energy demand. Originally developed for developed cities in the global North, there is now considerable interest in their application in the rapidly urbanising cities of the global South. This development history means that to date, UBEMs have not incorporated slums. With almost 30% of the global urban population living in slums and the vast majority of those in the global South, this paper considers the challenges of energy access for the urban poor in the global South and how people have been represented in UBEMs thus far. The implications of this failure to incorporate a large section of the urban population are considered. Participatory research methods are proposed as a method for collecting, processing and developing the data which is necessary to ground UBEMs and similar tools in the lived experiences of the urban poor