Advanced Urban Energy Planning: an interdisciplinary approach to improve heat decarbonization assessments

Urban areas have been recognized as the heart of the decarbonisation process, being potential drivers of sustainable or unsustainable paths. The necessary transition to cleaner and more sustainable cities recently raised the research attention on the possible ways to perform urban energy planning. However, there is still not a wellrecognized procedure and an agreed methodological framework to support urban energy planning, leading to inappropriate strategy definitions, directly focusing on the design of a pre-defined plan. This thesis has the primary objective to contribute in providing a theoretical-methodological framework to support urban energy planning by exploring, applying, adapting and combining with other disciplines, the principal energy system planning methods and tools. A review of scientific literature was performed to identify the state-of-art significant limitations on which the thesis was structured. Without seeking to replace other existing modelling approaches and without presupposing a full knowledge in the different research disciplines, this Ph.D. dissertation provides a basis for understanding how the weaknesses of the different approaches can be rectified by the strengths of others to move beyond traditional urban energy planning applications focused on the built environment. Comprehensive energy system methods and tools are necessary at the planning stage to quantitatively consider interactions among sectors and demand and supply options over long-term horizons. Nevertheless, the thesis confirms that while they are incredibly useful for planning purposes, they cannot be used alone for urban applications and should be combined with other methodologies. This need is mostly related to the necessity of disposing of a detailed and highly disaggregated description of the demand and of the spatiality to deal with specific urban needs (critical areas, liveability, built environment constraints). In particular, spatial analyses are fundamental in urban planning to considerably improve the quality of planning and decision-making processes through intuitive visualization maps. Furthermore, the involvement of stakeholders is key to the success of the planning procedure: they speed the data collection process, support definition of assumptions and a shared city vision (qualitative evaluations). Given the complex nature of urban energy planning, an interdisciplinary and integrated methodological procedure - based on the actions of knowing, understanding and planning – is therefore proposed. The procedure combines building physics, energy planning and territorial analyses to create a preliminary methodological background able to deliver technical, financial and environmental insights for the definition of energy plans. The proposed methodological framework was applied to a case study that fixed the research boundaries to the demand and supply side of the urban built environment of district-heated cities. The case study, on the one hand, provides numerical evidence to results and on the other hand offers a theoretical background for guiding urban planners, researchers, and decision-makers in future urban planning applications. As a result, the proposed integrated and comprehensive framework provides evidence of the multiple benefits of taking into account synergies between demand and supply, particularly in term of avoided additional investments. The scenarios analysis confirms that ambitious environmental targets can be reached at reasonable added costs if investments are appropriately channelled. The suggested research advances in urban energy planning will allow achieving more informed assessments of appropriate strategic investments, their life-cycle costs, and energy/ environment ambitions. All the recommended planning phases are fundamental, and the author suggests to push future research and practices to enhance the procedure by dividing it into a planning stage (knowing & understanding/ planning/ prioritizing & deciding) and into an operational phase (designing/acting/ monitoring & informing), leading to a bi-directional flow of information between planning and operational models

Advantages of coupling a woody biomass cogeneration plant with a district heating network for a sustainable built environment: a case study in Luserna San Giovanni (Torino, Italy).

One of the key strategies towards the European goals is the exploitation of local and renewable energy sources: the paper analyses the benefits and the feasibility of a woody biomass cogeneration plant in Luserna San Giovanni (Torino, Italy). The first part of the paper presents a graphical method to evaluate the thermal energy use of public and residential buildings. Then, after the selection of the buildings with both higher energy consumption and higher specific energy consumption, a thermal analysis allows the assessment of energy savings potential of these buildings. The results of this first analysis permit to estimate the effective and peak power of the plant considering different scenarios of buildings' renovation and then of heat distribution. The second part of the paper describes the pre-feasibility analysis of the district heating network supported by a GIS-based tool (Geographical Information System). Main results are the evaluation of the environmental and economic impacts of the biomass plant and of the connection to the district heating network on a short and long term horizon

modeling building energy demand profiles and district heating networks for low carbon urban areas

Abstract Urban energy consumptions growth has become an urgent topic that requires solutions for significantly reduce carbon emission in the next decades. This paper aims in exploring the integration of building performance improvement and low carbon district heat technological choices by considering the upgrade of conversion technologies, efficiency and the exploitation of local resources. The paper is based on a GIS-based model that spatially characterize the space heating demand of urban buildings. Starting from clustering buildings with similar thermo-physical characteristics, the total energy use of buildings can be depicted and compared with the energy balance data of the city in order to scale the bottom-up results for matching the total load. Reasonable energy efficiency measures are further proposed by considering three different scenarios up to 2050. Long-term building scenarios are applied to a district heating simulation model for investigating how the reduction of building heat demand will impact the district heating production and operations. In particular, the combination of the building model and the district heating model aims at exploring the effects of district network expansion or new low carbon investments from an economic and environmental perspective. The model has been successfully applied to the city of Turin, Italy and the city of Stockholm, Sweden. The flexibility of the approach may allow it to be easily adjusted to different urban areas for providing indications on cost-effective strategies for efficient, low-carbon heat solutions in integrated energy systems. Results highlight that finding synergies between the demand and supply sector will lead to environmental and economic benefits, in particular for district-heated cities

Linking Dynamic Building Simulation with Long-Term Energy System Planning to Improve Buildings Urban Energy Planning Strategies

The building sector is currently responsible of 40% of global final energy consumption, influencing the broader energy system in terms of new electricity and heat capacity additions, as well as distribution infrastructure reinforcement. Current building energy efficiency potential is largely untapped, especially at the local level where retrofit interventions are typically enforced, neglecting their potential synergies with the entire energy system. To improve the understanding of these potential interactions, this paper proposes a methodology that links dynamic building simulation and energy planning tools at the urban scale. At first, a detailed bottom-up analysis was conducted to estimate the current and post-retrofit energy demand of the building stock. The stock analysis is further linked to a broader energy system simulation model to understand the impact of building renovation on the whole urban energy system in terms of cost, greenhouse gas emission, and primary energy consumption up to 2050. The methodology is suited to analyze the relationship between building energy demand reduction potential and clean energy sources’ deployment to shift buildings away from fossil fuels, the key priority for decarbonizing buildings. The methodology was applied to the case study city of Torino, Italy, highlighting the critical role of coupling proper building retrofit intervention with district-level heat generation strategies, such as modern district heating able to exploit low-grade heat. Being able to simulate both demand and supply future alternatives, the methodology provides a robust reference for municipalities and energy suppliers aiming at promoting efficient energy policies and targeted investments

The role of urban form and socio-economic variables for estimating the building energy savings potential at the urban scale

In the past, to make the city liveable, the urban morphology has always be considered taking into account the climate, the buildings’ density and characteristics, the type of inhabitants and their social condition. On the contrary, recently in the urban planning process the morphological aspects are no more included even if they influence the energy consumption, the thermal comfort of the urban spaces and the district air quality. Moreover, the socio-economic conditions of inhabitants might strongly affect the lifestyle choice and behavior of building occupants and thus, the probability of success of urban planning measures for energy conservation. The present study aims to: 1) identify the correlation between thermal energy consumption for space heating and urban variables and 2) investigate the role of socio-economic variables in energy savings potential. The city of Turin is suitable for these analyses because it is characterized by different urban forms and urban spaces and by various characteristics of the population. By using a GIS tool, the district 3, chosen as a case study, has been divided into different urban textures considering their urban and socio-economic characteristics. The results of this study show that the measured energy consumption of single building depends on the physical building features (f.i. thermal insulation level, the compactness, the energy system efficiency etc.) but also on the urban form and the streets’ orientation. Another important result is that the social and economic situation of inhabitants has a relevant role in the success of sustainable policies. These conclusions may support urban planners in the definition of new urban areas with some “preliminary” energy savings measures at no cost and in formulating tailored policies according to socio-economic conditions from district to district. (Presented at the AIGE Conference 2015

Urban energy planning procedure for sustainable development in the built environment: A review of available spatial approaches

Urban and Regional Integrated Energy Planning is crucial to define transition strategies toward sustainable development and post-carbon cities; particularly, in the built environment sector which is one of the main responsible for energy consumption and carbon emissions. The paper aims at offering a systematic review of existing urban and regional energy planning approaches. This analysis is based on literature review. The reviewed papers are critically analyzed and discussed through a Meta-analysis and a SWOT analysis. The papers are classified in order to highlight the main research trends and to illustrate the most relevant characteristics of the principal approaches. This critical analysis of the papers highlights the lack of an holistic and integrated framework which is able to take into account the large variety of dimensions related to sustainable planning. A major achievement of this study is to provide information on how the various existing approaches can be integrated to handle the entire planning procedure adequately. The result provides a preliminary theoretical framework to integrate different approaches, identify the main barriers and future challenges in the field of research. This framework will help urban actors to develop energy planning projects, guiding them in the choice among a significant number of existing planning approaches

The Role of Nearly-zero Energy Buildings in the Definition of Post- Carbon Cities

Nowadays about 50% of global population lives in cities, responsible for about 70% of GHG emissions and by 2030 the urbanization rate will increase to over 75%. The paper discusses new emerging concept of “Post-Carbon” City, in which the “vision” consists in the opportunity of breaking the carbon-dependent system of urban areas. It provides inspiration to re-think urban re-development patterns. In this new vision buildings and occupant behaviour role and need for new comprehensive planning tools are investigated. The paper deals with a project that is undergoing study and represents a picture of the current situation related to “Post-Carbon” City topic

Caratterizzazione dei consumi energetici per la climatizzazione invernale di un’area urbana - CHARACTERIZATION OF BUILDING THERMAL ENERGY CONSUMPTION AT THE URBAN SCALE

In questi anni, la transizione verso nuovi modelli urbani “low carbon” ha incrementato lo sviluppo di nuovi processi di pianificazione energetica. Uno dei punti essenziali per sostenere lo sviluppo di piani energetici consiste in una corretta elaborazione di dati di natura eterogenea. Questo articolo introduce una metodologia per caratterizzare il parco edilizio residenziale di un area urbana in termini di distribuzione degli edifici per tipologia edilizia, destinazione d’uso e fabbisogni termici per il riscaldamento invernale. CHARACTERIZATION OF BUILDING THERMAL ENERGY CONSUMPTION AT THE URBAN SCALE The ongoing transition toward decarbonized urban energy systems has raised the attention on energy planning practices. Besides the multiple actors involved in the planning process, the complexity of the urban energy systems requires the elaboration of heterogeneous data. This paper introduces a GIS-based methodology for supporting the spatial characterization of the urban building stock in terms of building distribution, destination use and space heating energy consumption

Towards a New Integrated Spatial Decision Support System in Urban Context

The current growth of urbanization rate indicates that this trend is not going to stop, and therefore, it stresses the necessity of actions for mitigating the local and global pollution. Moreover, most of the actual stock is characterized by low energy performances since it pre-dates the energy regulation. The paper aims at addressing this issue by proposing the integration of Building Simulation (BS) approach, Multi-Criteria Analysis (MCA) methods and Geographic Information System (GIS) tool for developing a new Multi-Criteria Spatial Decision Support System (MC-SDSS) in urban context. The BS of relevant building archetypes allows to identify different resolutions of energy data: hour-by-hour data can be useful for demand-side management or renewable integration while aggregated data can be used for load forecasting and retrofit simulations. The MCA permits choosing between different building renovation alternatives by considering both qualitative and quantitative criteria. Moreover, the GIS support the method by creating geo-referenced databases. The method purposes in giving a comprehensive view to address the complexity of urban building energy planning; due to its flexibility, it can be applied to several urban areas. Three main phases characterize the study: i. overview of relevant existing techniques; ii. description of the integrated proposed method; iii. discussion and future application. The method can provide relevant feedbacks for ranking complex design energy option