Sustainable Urban Districts Research Articles

Economic and environmental optimal design of a multi-vector energy hub feeding a Local Energy Community

One of the main ways to reach the important targets of the European Commission in the energy field set by 2030 is to implement sustainable energy systems to cover electrical and thermal energy demands, as well as transportation needs, in urban areas. In the aforesaid scenario, multi-vector energy hubs consist of installing small and medium size power plants, mainly fed by renewable sources, and charging infrastructures for electric vehicles in sustainable urban districts. The optimal design of such systems can be faced from different points of view and using different methods, one of the most adopted being the development of mathematical programming algorithms typically aimed to minimize global costs and emissions. The contribution of this paper is to propose an innovative methodology to optimally design a multi-vector energy hub able to supply electricity and thermal energy, for space heating and cooling, to a set of buildings within a sustainable district acting as a local energy community. The developed mixed integer linear programming model is characterized by very detailed models of the technologies and by a multi-objective function which is proposed to evaluate the impact of the optimal solution on global costs and emissions. The proposed mathematical model is very comprehensive as it involves a wide range of energy technologies with detailed modelling by considering the impact of external ambient conditions and energy vector temperature values on the plant conversion efficiency, thus showing high replicability potential in real contexts. In the case study, the model is applied to a university campus in the North of Italy.

Resource Management as Part of Sustainable Urban District Development

Rising urban populations, limited natural resources (following the German Federal Environmental Agency, natural resources are resources that are part of nature. They include renewable and non-renewable primary raw materials, physical spaces (surface areas), environmental media (water, soil, air), flowing resources (e.g., geothermal, wind, tidal and solar energy) and biodiversity. It is irrelevant here whether the resources serve as sources for producing products or as sinks for absorbing emissions (water, soil, air)) and climate change require a new approach to urban planning. Recently, international, European and national programmes, concepts and framework documents have been created to promote the implementation of measures for more sustainability, resource efficiency and climate resilience in urban districts. In the funding measure of the German Federal Ministry of Education and Research’s “Resource-Efficient Urban Districts for the Future-RES:Z”, twelve funded research project networks are dedicated to understanding the impacts that urban districts have on the resources of land, water and material flows, as well as the resulting impacts on urban green spaces and energy issues. By considering the different resources involved, it is shown that the optimisation of their use cannot take place independently of each other. This may even lead to conflicting goals. Use conflicts can be recognised at an early stage and measures can be tailored to the specific neighbourhood context when applying an integrated approach that provides a common view on all of the aforementioned resources. Special attention is paid to solutions which create numerous benefits i.e., multifunctionality. The RES:Z funding measure utilises living labs for the research on and implementation of solutions. This lays the foundation for a sustainable transformation of urban districts and the basis for further research.

The 15-minute city: interpreting the model to bring out urban resiliencies

In a globally connected world and increasingly smart cities, the demand for living in a physical neighborhood where one can walk and cycle among familiar people and a variety of services is always alive. It is a quality of life which meets the deep desire of community and place identity. In this regard, the 15-minutes city is the contemporary version of the classical “human measure”. The model offers a refreshing chrono-centric vision for the city that prioritizes people’s time, energy and physio-psychological health by relieving their daily commutes. The recent pandemic clearly showed this potential; the daily outdoor movement by soft mobility allowed for social life even during lockdown periods. The paper is subdivided into two main components: a theoretical discussion of the 15-minute city model as part of a broader sustainable urban planning narrative, and a practical application mapping the potentials of Milan as a 15-minute city, focusing on population distribution and urban fabric structure as a measure of performance evaluation. The emergence of the 15-minute model rebalances the building volume concentration of the consolidated Transit Oriented Development paradigm; suggesting an innovative and more articulated vision. The 15-minute approach, rooted in the organic planning of the ‘60, is pushed by the covid-19 emergency, making treasure of the experience of urban regeneration masterplans of the last decade. The approach falls in line with real estate strategies for place making, which aim to create new sustainable urban districts that are pedestrian oriented and carbon free. After interpreting the international framework of urbanism trends with respect to the 15-minute model, the paper focuses on the Milan case. The potentials for neighborhoods across the city of Milan is investigated to conform to an inclusive 15-minute city model, using fully-fledged and innovative mapping of proximity. This analysis aims to explore the resilience of urban resources to support walkable living environments with a guaranteed basic level of accessibility to daily needs by walking. The support to this model offered by soft mobility modes and micro-mobility devices is also raised. The results show, in a number of urban neighborhoods, a limited level of walkability although related to a spatial city structure which is able to be regenerated as a dense and effective network of 15-minute neighborhoods through tactical urbanism actions on existing open spaces and soft mobility policies, combined with long term strategies (infrastructure capacity and digital upgrading). It is a first methodological test which opens up the research towards a new inclusive concept of accessibility.

Eco-districts and data-driven smart eco-cities: Emerging approaches to strategic planning by design and spatial scaling and evaluation by technology

In recent years, the world has witnessed significant progress in implementing numerous eco-district and eco-city projects, which are under the banner of experimentation or seen as sites of innovation. Indeed, the rise of such initiatives serves as a sign of renewed attempts to experiment or innovate in designing urban futures in an increasingly urbanized and datafied society. In light of this, a number of alternative models of eco-urbanism have been proposed by scholars and promoted by policy makers. The prominent among these models are sustainable urban districts and data-driven smart eco-cities. At the core of these models is a range of compact and ecological design strategies and static and dynamic conceptions of spatial scaling. These are intended to produce and boost the benefits of sustainability on the basis of a set of integrated approaches—increasingly supported by big data technologies—as a way to overcome new challenges and introduce new solutions. Based on two case studies conducted on three of the ecologically and technologically leading cities in Europe—Stockholm, Malmö, and Barcelona, this paper analyses and discusses the role and relevance of integrating density, mixed land use, greening, and low-energy buildings to the sustainability of emerging eco-districts; the new conceptions of cities and their spatial scales in the context of data-driven smart eco-cities; and the opportunities and challenges of smart urban metabolism with respect to the evaluation of eco-districts. This study shows that combining compact and ecological design strategies improves the performance of eco-districts with respect to the three dimensions of sustainability, as well as paves the way for their balanced integration for producing synergistic effects. Also, this study highlights the innovative potential and enabling role of urban computing and intelligence in transforming the spatial scaling of data-driven smart eco-cities through generating the kind of designs that increase the effects of sustainability as outcomes of processes. Moreover, this study reveals the advantages of the data-driven approach to the analysis of the flows of resources in urban environments in relation to the evaluation of sustainable urban district development. This paper concludes that data-driven smart planning and evaluation holds great potential for facilitating progress towards achieving the goals of sustainability thanks to the proven role and untapped potential of big data technologies in monitoring, understanding, and analyzing urban processes and systems in real-time.

Smart Eco-City Strategies and Solutions for Sustainability: The Cases of Royal Seaport, Stockholm, and Western Harbor, Malmö, Sweden

Sustainable urbanism is seen today as one of the keys towards unlocking the quest for a sustainable society. As a central paradigm of sustainable urbanism, the eco-city is promoted by global and local policies as one of the preferred responses to the challenges of sustainable development. It is argued that eco-city strategies are expected to deliver positive outcomes in terms of providing healthy and livable human environments in conjunction with minimal demand on resources and thus minimal environmental impacts. As such, it is pertinent to examine how the eco-city model and especially its three sustainability dimensions is practiced and justified in urban planning and development at the local level. This is motivated by the increased interest in developing sustainable urban districts. In this light, this study seeks to answer the following two questions: What are the key strategies of the eco-city district model, and in what ways do they mutually complement one another in terms of producing the expected tripartite value of sustainability? To what extent does the eco-city district model support and contribute to the environmental, economic, and social goals of sustainability? To illuminate the phenomenon of the eco-city district accordingly, a descriptive case study is adopted as a qualitative research methodology, where the empirical basis is mainly formed by urban planning and development documents in two eco-city districts—Royal Seaport, Stockholm, and Western Harbor, Malmö, Sweden—in combination with qualitative interview data, secondary data, and scientific literature. This study shows that the eco-city district models of SRS and Western Harbor involve mainly design and technology, supported with behavioral change, as key strategies and solutions for achieving urban sustainability. Design encompasses greening, passive solar houses, sustainable transportation, mixed land use, and diversity. And technology comprises green technologies, energy efficiency technologies, and waste management systems. Design contributes to the three goals of sustainability, and technology contributes mostly to the environmental and economic goals of sustainability. Behavioral change is associated with sustainable travel, waste separation, and energy consumption. Moreover, at the core of the eco-city district model is the clear synergy between the underlying strategies in terms of their cooperation to produce combined effects greater than the sum of their separate effects with respect to the benefits of sustainability. Further, this study demonstrates that while the environmental, economic, and social goals of sustainability are represented in eco-city district strategies on a discursive level, institutionalized planning practices show that the environmental goals remain at the core of planning, while the economic and social goals still play second fiddle. Nevertheless, new measures have recently been implemented in Western Harbor that are expected to strengthen their influence over urban development practices, whereas the Royal Seaport program mainly focuses on the environmental and some economic aspects, which is a shortcoming that should be recognized and dealt with.

Electric Vehicles and Storage Systems Integrated within a Sustainable Urban District Fed by Solar Energy

In this paper, an optimization model is defined for the design of a smart energy infrastructure integrating different technologies to satisfy the electrical demand of a given site. The considered smart energy infrastructure includes a photovoltaic plant, electrical storage systems, electric vehicles (EVs), and charging stations. The objective function of the optimization model considers the costs related to the installation and maintenance of the considered technologies, as well as the costs associated with the energy exchanges with the external grid. A very extensive numerical analysis is reported in the paper, referred to a test case in a real site in Liguria Region, in the north of Italy. Many scenarios are analyzed and discussed, with specific attention to evaluate the role of electric mobility within a smart energy infrastructure and a focus on EVs acting as mobile storage systems.

An Energy Management Platform for the Optimal Control of Active and Reactive Powers in Sustainable Microgrids

This paper presents an energy management platform based on a receding-horizon scheme for the optimal control of active and reactive power flows in microgrids, including small-size photovoltaic, combined heat and power, wind generation, mini-hydro, and energy storage. The objective function to be minimized can be set both on the daily operational costs (economic indicator) and on the global CO2 emissions of the system (environmental indicator), whereas decision variables are the production schedules of the generators and the power flows across the grid. The tool includes the technical constraints characterizing low voltage/medium voltage (LV/MV) microgrids and gives the user the possibility to select different models for the electrical network (nonlinear power flow equations, linear approximation, and single bus-bar) and different optimization ranges. The energy management system has been validated through an experimental campaign on the smart polygeneration microgrid of the University of Genoa, which provides electricity and thermal energy to the Savona Campus, an “open-air” demo-site of an environmentally sustainable urban district with a population of about 2200 people. The results of the tests on the field highlight the robustness of the developed platform and the capability of the receding-horizon algorithm at the core of it of successfully treating data uncertainties.

Towards a sustainable district: a streamlined Life cycle assessment applied to an Italian urban district

The literature shows a lack of environmental indicators able to support the transition from a sustainable to a smart city framework, since the priority area “built environment” is indeed more comprehensively addressed by urban sustainability assessment systems (13%), than by smart city frameworks (4%) [12].As “smaller cities inside a larger agglomerate” [19], urban districts play a key role in defining effective and innovative paths toward a smarter city, but defining a sustainable urban district is not straightforward, and even less is capturing the induced impacts due to interactions between individual buildings and their surround urban setting [23]. The adoption of a quantitative method for evaluation, such as Life Cycle Assessment (LCA), emerges as an essential step for this purpose [24].This article explores the application of a streamlined LCA on the urban district main issues (buildings, energy, water and waste), referring to an urban retrofitting intervention of Bolognina neighbourhood.A set of mitigation strategies developed by an interdisciplinary research group (joining researcher team from the Department of Architecture of the University of Bologna and Institute of Sustainability in Civil Engineering of the RWTH Aachen University) provides the reference framework for the application deepened within the article. This work is a first application of LCA to a case study but it not includes a comprehensive sustainability framework yet, further activities are planned to finalize the analysis, e.g. taking account of social dimension by applying Social Life Cycle Assessment.

Living Labs and Partnerships for Progress: How Universities can Drive the Process towards the Sustainable City

Universities can play an active role in facilitating the deployment at a wide scale of the sustainability concept, strictly cooperating with public-private institutions and civil society. Following this path, the University of Genoa, Italy, decided to transform its Savona Campus into a Living Lab aimed at creating a model of a sustainable urban district, to be replicated at the city level with specific implementation projects. Different actions on sustainable energy, smart environment and social health & wellbeing have been deployed: energy efficiency interventions, smart grid connected to a zero-emission building, electrical mobility and outdoor sport activities. All the projects have been developed with the active involvement and the empowerment of the Campus community (students and faculty) and thanks to important collaborations with local public institutions and industrial companies.

The Role of Urban Pattern Indicators in Achieving Sustainable Urban Forms in the Developed Countries - A Pragmatic Evaluation of Two Sustainable Urban Contexts

Since cities are constantly changing, their new forms and activities are developed according to their patterns and physical arrangements. Sustainable urban forms are currently a widely discussed topic in the concept of urban sustainability. The physical forms of cities can be conceptualised as two interlocking planes. The first comprises the spatial distribution of activities and buildings. The second is made up of the pattern of streets, parks and the public realm. Sustainable integration between these layers leads to a compatibly built environment. This paper intends to formulate sustainable urban form indicators as a conceptual framework model that provides a comprehensive understanding of how sustainability can be evaluated and measured according to the pattern of any built environment. This framework consists of eight indicators: Accessibility, Connectivity, Compatibility, Diversity, Nodality, Density, Identity, and Adaptability. Accordingly, two of the most significant sustainable urban districts have been chosen for field study. The first is the Hammarby residential district in Stockholm, Sweden and the second is the Vauban residential district in Freiburg, Germany. The research concludes that good performance of urban pattern indicators in these developed communities may motivate, inform and improve design strategies for achieving a more sustainable urban context.

Can Stockholm Royal Seaport be part of the puzzle towards global sustainability? – From local to global sustainability using the same set of criteria

Urban sustainable development is today seen as one of the keys towards unlocking the quest for a sustainable world. One feature of urban sustainability is the increased interest in developing sustainable urban districts. For many of these developments, guiding sustainability documents are developed to frame future goals. However, few of these documents specify on which grounds they determine the sustainability of goals and they are largely developed as independent islands of local sustainability. This is unfortunate as cities and their districts are fully dependent on surrounding environments. Failing to include a holistic approach into the local planning increases the risk of sub-optimisation, future lock-ins and missed targets on a higher level. The aim of this study is to analyse whether the environmental and sustainability programme for Stockholm Royal Seaport, a new urban district in Stockholm, Sweden, can guide development of the district towards holistic ecological sustainability. By using the Framework for Strategic Sustainable Development a holistic template for an ecologically sustainable planet has been described, important sectors for the built environment have been identified and the environmental and sustainability programme for the district has been analysed. This study showed that the vision and operational goals put forward in the Stockholm Royal Seaport programme complies relatively well with the designed template. However, important deviations in all sectors but land use have been identified. These deviations arise in the translation process between theory and practice. The vision for the district and the implementation phase are not aligned due to too narrow a perspective of a sustainable urban district, lack of robust sustainability principles including use of such to identify key strategic questions. In addition to the lack of an all-embracing conceptual framework, there is also a lack of structures for cooperation between stakeholders and conflicts between local and regional agendas. Use of a unifying framework can describe desirable future scenarios where the local level does not contribute to violation of the universal sustainability principles and identify step-wise routes towards such scenarios.

Interconnection between Scales for Friendly and Affordable Sustainable Urban Districts Retrofitting

The EU FP7 project FASUDIR (Friendly and Affordable Sustainable Urban Districts Retrofitting) supports the mobilization of the building retrofitting market towards 2020-2050 EU-targets through an Integrated Decision Support Tool (IDST), a software based on a new methodology that will help decision makers identify the best energy retrofitting strategy to increase the sustainability of the whole district. Improving the sustainability of urban environments is a interscalar problem, addressed through a multiscalar and multidirectional approach. A comprehensive urban scale strategy considers the working scale, but the measures at building scale have to be coherent with the global objectives at district and city scale. The FASUDIR IDST and methodology interconnect and visualize information across scales, ensuring comprehensive diagnoses and proper implementation of strategies. Due to the complexity of urban sustainability, interscalarity and multiscalarity, first it has been necessary to identify the possible scales of analysis, to capture various themes and to highlight the horizontal and vertical interconnections between different components. Multiscalarity and Interscalarity affect the three phases of the sustainable retrofitting cycle: diagnosis, decision making and management. The identification of the impact of district solutions on buildings (and vice versa) and their compatibility across scales has been addressed through interconnected building and district Key Performance Iindicators (KPIs). The intervention phases at building level generate new information about specific buildings, enabling more accurate decision making at district level. The methodology articulates the structure of the new information and the feedback generated during the process. To allow information interconnection a strategic information management is key. A multiscale information model based on CityGML, a standard data model issued by the OGC (Open Geospatial Consortium), will be the baseline structure for all the district-scale information (geometric and semantic) that is necessary for decision making and management, organized into a single interoperable data model that will integrate information from different fields and at different levels of detail.The research leading to these results has received funding from the European Union Seventh Framework Programme (FP7/2007- 2013) under grant agreement n̊ 609222.

The sustainable urban district of vauban in freiburg, germany

The sustainable urban district of vauban in freiburg, germany

The development of a sustainable urban district in Hammarby Sjöstad, Stockholm, Sweden?

By 2012, Hammarby Sjostad, a former large industrial harbor area in southern Stockholm, Sweden, will be a fully developed residential district containing approximately 11,000 apartments and accommodating 35,000 people. The transformation of the area began in 1996, and the development soon became renowned for its ambitious environmental program, inspired by Agenda 21 (United Nations in Rio declaration on environment and development. United Nations Department of Economic and Social Affairs (DESA), Rio de Janeiro, 1992) and the Sydney 2000 Olympics in Australia (Newman in Landsc Urban Plan 44:219–226, 1999). Using results based on literature reviews, in-depth interviews, discussions with focus groups, and quantitative data, this paper attempts to gain insight into how the environmental program influenced the planning and performance of the district with regard to sustainable urban development. In doing so, three important conclusions were maintained that could be valuable for similar projects concerning the planning and development of sustainable urban districts. First, the environmental program proved vital to the development process of Hammarby Sjostad, specifically in its drive to create a sustainable urban district. When planning on improving the sustainability of future districts, such a program should be introduced and integrated earlier in the planning stage of the district. Second, the metabolic flows of Hammarby Sjostad were reduced as a result of the integrated system—the Hammarby Model—of Hammarby Sjostad. In order to reduce the metabolic flows in future urban districts even further, it is important to facilitate the integration of technical innovations into existing integrated systems. Third, this case study showed that there was a loss of valid and credible data related to the aims and goals of the environmental program of Hammarby Sjostad. In future urban districts, it is of the utmost importance to include a clear structure of the assessment process in the environmental program, which would ensure the quality of gathered data and facilitate the development of even better sustainable urban districts in the future.