• Energy Research

With the change of energy regulations in the Geneva canton, exergy and exergy system efficiency entered into everyday life. Exergy is defined as the potential of maximum work which can ideally be obtained from each energy unit. This analysis allows coherent energy system evaluations while making it possible for urban energy planning actors to identify the most effective solutions and policies.

Cities play a dual role in the field of energy and integrated planning. They function as institutional planning and decision making bodies and interfere as actors, e.g. as project developers or launching customers. In the first case their attempts at integrated plans are often unsuccessful in integrating vision, goals and instruments of all stakeholders so that waste, water, energy cycles, urban planning and budgets proceed with no connection to each other. TRANSFORM Project “Transformation Agenda for Low Carbon Cities” (FP7) tries to improve the integrated energy policy and decision making process of cities, both at a strategic and operational level, by providing the cities with a framework based on overall planning experiences and on-the-field projects and qualitative and quantitative analysis support models. The project intends also to make a step further in the quality of research, by providing a replicable and tested framework for the production of a strategic Transformation Agenda for the city as a whole, combined with district Implementation Plans. Tema. Journal of Land Use, Mobility and Environment, 2014: INPUT 2014 - Smart City: planning for energy, transportation and sustainability of the urban system

With the change of energy regulations in the Geneva canton, exergy and exergy system efficiency entered into everyday life. Exergy is defined as the potential of maximum work which can ideally be obtained from each energy unit. This analysis allows coherent energy system evaluations while making it possible for urban energy planning actors to identify the most effective solutions and policies

The MEU GIS-enabled web-platform [1] has been developed in close collaboration with four Swiss cities. The tool enables detailed monitoring and planning for both energy demand and supply at individual building, neighborhood and whole city scale (http://meu.epfl.ch). This web-platform acts like an interface between different tools and allows to establish detailed energy balances for entire cities comprising several thousand buildings. In its present configuration, the MEU tool does not allow yet to simulate energy networks behaviors, based on the real or projected energy demand in an urban zone. In order to meet this need from energy utilities partners, a specific data model, as well as an user-interface giving access to networks attributes and edition/simulation tools were developed, which will be then functionally integrated in the MEU platform. The idea is to create a “Natural Gas Networks” module built for energy utilities. The objectives of this project within the larger MEU endeavor were the following: - Create a platform gathering topological and geo-referenced data - Develop a gas network pre-design/planning methodology including demand characteristics and gas supply for buildings in a selected area. - Interface with gas distribution system operators existing tools and add new functionalities within a single platform. - Include gas distribution system operator constraints and operational realities in the pre-design/planning process. In order to achieve those objectives, two tools and several visualization concepts have been created, along with an ad hoc data model: (i) a data model able to allow data import, storage and centralization from energy utilities databases: networks, buildings demands and specifications, as well as interface between edition, simulation and visualization tools; (ii) a network edition tool prototype (LEAFLET JavaScript based web page), which allows to display a network on a map, to add/delete or drag&drop pipes, nodes, consumption and biogas production/injection points and pressure let down stations; (iii) a network flows, and pressures simulation device (MATLAB® compressible fluids model) which computes the network behavior for each hour (pressures, flows, power equivalent and temperatures in each point); (iv) a detailed mock-up for visualization and display concept with interactive and GIS data: buildings area, networks paths, pipes characteristics, results from simulation, studied area energy balance, etc. This paper focuses more specifically on the visualization and network edition tool, as well as simulation results interactive representation on the MEU platform.

This paper describes the use of Soft Systems Methodology (SSM) as a tool for problem structuring, which is the first phase encompassed in a methodological approach currently under development to provide decision support based on Multi‐Criteria Decision Analysis (MCDA) in energy planning problems in an urban context. In order to apply the methodology to a real‐world problem, a medium sized Portuguese city has been chosen as the decision setting. SSM is used for characterizing as precisely as possible the decision problem context, identifying the main stakeholders and their relations, and discerning the relevant criteria at stake for each one. Future work directions based on this phase are also envisaged. Article in English. Operacinės sistemos metodologijos taikymas planuojant miesto energetiką Santrauka. Straipsnyje aprašoma operacinės sistemos metodologija (OSM), kuri bus taikoma kaip daugiakriterinės analizės metodais pagrįsta sprendimų paramos sistema miesto energetikos planavimo problemoms spręsti. Siekiant metodologiją pritaikyti realiame gyvenime, eksperimentui buvo parinktas vidutinio dydžio Portugalijos miestas. Operacines sistemos metodologija taikyta kuo tiksliau nustatant pagrindines problemas, identifikuojant pagrindines suinteresuotas šalis ir jų santykius, nustatant vienas kitam įtaka darančius rodiklius. Numatytos būsimos darbo kryptys. Reikšminiai žodžiai: operacinė sistemos metodologija, daugiakriterinė sprendimų analizė, miesto energetikos planavimas. First published online: 10 Feb 2011

In order to facilitate urban energy management and energy planning, the project MEU developed a web based tool as a decision support system for decision makers. Using a web based approach minimizes the effort on the client site as no software needs to be installed or be updated on the personal computer. Updates are published by the development team on the central server. During the first phase of the project, First, data are collected based on the buildings in the federal land registry offices' data. The data contains all the relevant elements in the energy conversion chain of a given city over the last couple of years available on an annual basis: meteorological data, a list of accessible resources, energy conversion technologies, energy distribution networks and buildings as consumers of different energy services. Second, all buildings and networks are geo-referenced to allow plotting maps. This already gives a comprehensive overview of the current energy state of a city. Third, measurements of (annual) energy consumptions are introduced allowing the performance monitoring. With the annual energy consumption of each energy conversion system, the current state of a city can be monitoring and compared to previous years. Fourth, this data is structured and completed for the use in the energy simulation software: CitySim for the dynamic building energy demand simulation and EnergyTechnology for the calculation of the energy conversion technologies. Especially the completion demands supplementary work as the data sets are often not very comprehensive. Therefore default values based on the current Swiss norms and previous publications are used to minimize the errors made in the simulations. As a set of default values is provided in the platform, it runs even if only a small data set is imported. When more information is available such as the energy consumption or the physical building data, the platform can easily be updated to increase the accuracy of the results. With this approach, urban energy flows from resource to useful energy can be tracked and inefficiencies can be spotted easily along the conversion processes. Furthermore, the creation of scenarios based on a given actual year allows for example the quick comparison of different energy conversion scenarios for different technological measures introduced in a city or the evaluation of refurbishment strategies on the energy demand. The maps allow to geo-localize priority areas and help representing the results.

Cities are emitting worldwide around 70% of all greenhouse gas emissions. To reduce this large share, cities aim to develop energy strategies, implemented as a set of measures to mitigate energy demand and ensure a sustainable energy supply for the built environment. Thus, adequate IT tools are required to support the urban energy planning processes. However, developers of such tools i.e. modellers of complex urban energy system face four main challenges: (i) Supporting the perspectives of different involved stakeholders (i.e. targeted information supply). (ii) Quantifying the impact of developed strategies and simplifying the presentation of their impact (so that it is understood by all the stakeholders). (iii) Integrating of the measures that compose the strategy, also in terms of stakeholders-implication. (iv) Ensuring the replicability of the system in different cities that have different data availabilities or stakeholders. This dissertation addresses the problem in an incremental approach, where an ontology is progressively developed. Measures to be implemented are defined. Stakeholders that each measure involves are identified, and questions they raise for their decision making are listed, as competency questions of the ontology. Computation models to answer these questions are identified (to be potentially reused) or developed, taking into consideration the data availability in the city. The semantics used in these models are then captured and classified within the ontology. Then, the decision-making-knowledge of the stakeholders is integrated within the ontology. Finally, the ontology is used through a web-map-based interface. The proposed solution anticipates the potential decisions of the different stakeholders, easing the progress of the energy planning process, typically happening in workshops or forums in collaboration with different stakeholders. The approach has been applied to develop a planning support system that supports two measures: solar photovoltaics planning and building refurbishment planning. The system has been applied and tested in a district (4th District) in the city of Vienna.

The electricity, heating, and transport sectors in urban areas all have to contribute to meeting stringent climate targets. Cities will face a transition from fossil fuels to renewable sources, with electricity acting as a cross-sectorial energy carrier. Consequently, the electricity demand of cities is expected to rise, in a situation that will be exacerbated by ongoing urbanisation and city growth. As the supply of electricity to cities is limited by transmission capacity from the national grid, city planning requires a detailed understanding of the options available for: decentralised electricity generation; synergies between the heating and electricity sectors; and flexibility through energy storage technologies. This work proposes an optimisation model that interconnects the electricity, heat, and transport sectors in cities. We analyse the investments in and operation of an urban energy system, using the City of Gothenburg as an example. We find that the availability of electricity from local solar PV together with thermal storage technologies increase the value of using power-to-heat technologies, such as heat pumps. High biomass prices together with strict climate targets enhance the importance of electricity in the district heating sector. At low biomass prices, CHP units fired by biomass are utilized over the whole model year. The model will be developed further in future studies, to include details on electric vehicle charging and other energy carriers.