620 research outputs found

    Transition to electric buses networks: a mixed-fleet approach

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    As the environmental concerns increase, companies are called upon to adopt environmentally friendly solutions in their operations. Since the transportation sector counted for about ¼ of the global carbon dioxide emissions in 2010, transport providers agencies have been aiming to incorporate electric vehicles in their operations. This trend is observable in bus urban networks. In order to electrify the bus fleet and make the respective fleet planning decisions, it is necessary to address the necessary infrastructure requirements considering some operational constraints and the company´s objectives. This dissertation proposes a tool based on an optimization model, the MixedBusFleet, that aims to support transport providers to achieve the electrification of their fleets by minimizing investment costs, operational costs and the external costs of emissions. The MixedBusFleet model considers: (i) location of charging station; (ii) frequency of charging; (iii) charging strategy; (iv) battery type; (v) fleet dimension and; (vi) an emissions factor. The literature analyzed throughout this study identified that there is no previous work that incorporates all these planning objectives in one approach. Therefore, the proposed model aims to fill this gap. To illustrate the potential of the model, it was applied to part of the network of a public transport company operating in Lisbon. The case study comprised of 17 bus routes with predefined demand. The results showed that 133 buses are required to serve all the demand requiring a total investment of €24 950 000 and 5 fast charging facilities were installed in final stops.À medida que as preocupações ambientais aumentam, as empresas são incentivadas a adotar soluções ecológicas nas suas operações. O setor de transporte foi responsável por cerca de ¼ das emissões globais de dióxido de carbono em 2010, então, as empresas de transportes têm procurado incorporar veículos elétricos nas suas operações. Para eletrificar uma frota de autocarros e tomar as respetivas decisões de planeamento, é necessário considerar as necessidades de infraestruturas, algumas restrições operacionais e os objetivos da empresa. Esta dissertação propõe uma ferramenta baseada num modelo de otimização, o MixedBusFleet, que visa apoiar as empresas na eletrificação das suas frotas, minimizando os custos de investimento, custos operacionais e os custos externos de emissões. O modelo MixedBusFleet considera: (i) localização da estação de carregamento; (ii) frequência de carregamento; (iii) estratégia de carregamento; (iv) tipo de bateria; (v) dimensão da frota e; (vi) um fator de emissão. A literatura analisada ao longo deste projeto não identificou estudos que incorporassem todos os objetivos de planeamento indicados numa abordagem. O modelo proposto visa então, preencher essa lacuna. Para ilustrar a o potencial do modelo, o mesmo foi aplicado a parte de uma rede de transporte público em Lisboa. O estudo de caso é composto por 17 rotas de autocarros com procura pré-definida. Os resultados revelaram que são necessários 133 autocarros para satisfazer a totalidade da procura, o que requer um investimento total de €24 950 000 e que é necessária a instalação de 5 estratégias de carregamento rápido em paragens

    Multi-objective Smart Charge Control of Electric Vehicles

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    With the increasing integration of electric vehicles and renewable energy sources in electricity networks, key opportunities in terms of a cleaner environment and a sustainable energy portfolio are unlocked. However, the widespread deployment of these two technologies, can entail significant challenges for the electricity grid and in a larger context for the society, when they are not optimally integrated. In this context, smart charging of electric vehicles and vehicle-to-grid technologies are being proposed as crucial solutions to achieve economic, technical and environmental benefits in future smart grids. The implementation of these technologies involves a number of key stakeholders, namely, the end-electricity user, the electric vehicle owner, the system operators and policy makers. For a wider and efficient implementation of the smart grid vision, these stakeholders must be engaged and their aims must be fulfilled. However, the financial, technical and environmental objectives of these stakeholders are often conflicting, which leads to an intricate paradigm requiring efficient and fair policies. With this focus in mind, the present research work develops multi-objective optimisation algorithms to control the charging and discharging process of electric vehicles. Decentralised, hybrid and real-time optimisation algorithms are proposed, modelled, simulated and validated. End user energy cost, battery degradation, grid interaction and CO2 emissions are optimised in this work and their trade-offs are highlighted. Multi-criteria-decision-making approaches and game theoretical frameworks are developed to conciliate the interests of the involved stakeholders. The results, in the form of optimal electric vehicle charging/discharging schedules, show improvements along all the objectives while complying with the user requirements. The outcome of the present research work serves as a benchmark for informing system operators and policy makers on the necessary measures to ensure an efficient and sustainable implementation of electro-mobility as a fundamental part of current and future smart grids

    V2G Services for Renewable Integration

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    With the proliferation of renewable energy sources (RES) and the growing consumer demand for plug-in hybrid (PHEV) and total electric vehicles (EV), the limitations of the aging electrical grid distribution infrastructure is becoming more and more apparent. The development of better infrastructure, therefore, is at the forefront of research. The development of a smart grid, a bidirectional distribution infrastructure, will allow for two-way “communication” of power distributors and aggregators with multiple smart platforms, such as smart buildings, homes, and vehicles. The focus of this chapter is to outline the means of (electrical) vehicle to (smart) grid (V2G) interactions and how attaining a synergistic relationship is vital to improving the way power is distributed. The ability of fleets of EVs to act as a unit for excess power storage allows for the increased integration of RES into existing grid infrastructure and smart grids in the future through the bidirectional communication; providing support, giving back stored power into the grid to lessen the load felt by generation utilities, augment stochastic RES when generation is not meeting demands, lowering costs for both sellers and buyers, and above all, working toward the betterment of Earth

    Advanced Communication and Control Methods for Future Smartgrids

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    Proliferation of distributed generation and the increased ability to monitor different parts of the electrical grid offer unprecedented opportunities for consumers and grid operators. Energy can be generated near the consumption points, which decreases transmission burdens and novel control schemes can be utilized to operate the grid closer to its limits. In other words, the same infrastructure can be used at higher capacities thanks to increased efficiency. Also, new players are integrated into this grid such as smart meters with local control capabilities, electric vehicles that can act as mobile storage devices, and smart inverters that can provide auxiliary support. To achieve stable and safe operation, it is necessary to observe and coordinate all of these components in the smartgrid

    Accelerating bus electrification : enabling a sustainable transition to low carbon transportation systems

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    Thesis: M.C.P., Massachusetts Institute of Technology, Department of Urban Studies and Planning, 2018.Thesis: S.M. in Transportation, Massachusetts Institute of Technology, Department of Civil and Environmental Engineering, 2018.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (pages 136-143).With growing agreement that credible pathways to zero carbon electricity exist, many support the notion that widespread electrification of the transportation sector will be an essential strategy for meeting scientifically-based midcentury climate goals. While transit buses have a relatively small impact on greenhouse gas emissions, they have a larger impact on urban air quality, have commercially available in-service electric models, and have historically commercialized clean technologies that enabled deployment in the rest of the heavy duty vehicle sector. This thesis seeks to understand what factors hinder or enable transit agencies to go beyond initial pilots to largely or wholly electrify their fleets, with the goal of understanding potential policies and strategies that could accelerate such a transition, without inhibiting existing or expanded transit service that also plays a key role in reducing carbon emissions, in order to improve local air pollution and support accelerated electrification of trucks and other heavy duty vehicles. Using public transit fleets in California, Kentucky, and Massachusetts as case studies, this thesis utilizes quantitative total cost of ownership and well-to-wheels greenhouse gas and air pollutant emissions analysis, and analysis of qualitative interviews with transit agency representatives to investigate the barriers, drivers, and potential solutions that could hinder or enable an accelerated yet sustainable transition to an electrified bus fleet. A total cost of ownership analysis reveals that electric buses may already be more cost effective than diesel buses in many case study utility service areas primarily due to fuel and maintenance cost savings, but are sensitive to key parameters such as annual mileage, electricity tariffs that vary widely by location, fossil fuel costs, policy context, and anticipated maintenance savings, and that cost savings from electric buses are likely to increase over time primarily due to anticipated reductions in battery costs and a faster increase in fossil fuel prices than electricity prices. While multiple agencies interviewed in California were planning to fully electrify their fleets, primarily due to political pressure and internal leadership, outside California where less supportive policies exist, fewer agencies were planning to procure additional electric buses, primarily due to high first cost and undesirable tradeoffs with maintaining or expanding transit service levels. Interview respondents reported other substantial barriers as well, such as oversubscribed discretionary grant programs, charging infrastructure costs, electricity costs, additional operational complexity, and performance uncertainty and risk, suggesting a need for multiple complementary policies to overcome these barriers and ensure agencies can transition to a new technology without impacting service. Important interventions identified include pursuing favorable electricity tariffs and electric charging infrastructure incentives through regulatory changes, and further leveraging limited public funds such as the Volkswagen settlement to develop low cost financing approaches similar to those utilized in the clean energy sector that can pledge anticipated operating savings to afford the incremental upfront cost. A set of complementary policies is then recommended to accelerate bus fleet electrification in each case study context, in order to achieve carbon reduction and air quality improvements for low income, urban communities without impacting transit service levels, and to help lead the way for the transition of other heavy duty fleets.by Kelly Blynn.M.C.P.S.M. in Transportatio

    SEEV4City INTERIM 'Summary of the State of the Art' report

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    This report summarizes the state-of-the-art on plug-in and full battery electric vehicles (EVs), smart charging and vehicle to grid (V2G) charging. This is in relation to the technology development, the role of EVs in CO2 reduction, their impact on the energy system as a whole, plus potential business models, services and policies to further promote the use of EV smart charging and V2G, relevant to the SEEV4-City project

    State-of-the-Art Assessment of Smart Charging and Vehicle 2 Grid services

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    Electro-mobility – especially when coupled smartly with a decarbonised grid and also renewable distributed local energy generation, has an imperative role to play in reducing CO2 emissions and mitigating the effects of climate change. In parallel, the regulatory framework continues to set new and challenging targets for greenhouse gas emissions and urban air pollution. • EVs can help to achieve environmental targets because they are beneficial in terms of reduced GHG emissions although the magnitude of emission reduction really depends on the carbon intensity of the national energy mix, zero air pollution, reduced noise, higher energy efficiency and capable of integration with the electric grid, as discussed in Chapter 1. • Scenarios to limit global warming have been developed based on the Paris Agreement on Climate Change, and these set the EV deployment targets or ambitions mentioned in Chapter 2. • Currently there is a considerable surge in electric cars purchasing with countries such as China, the USA, Norway, The Netherlands, France, the UK and Sweden leading the way with an EV market share over 1%. • To enable the achievement of these targets, charging infrastructures need to be deployed in parallel: there are four modes according to IEC 61851, as presented in Chapter 2.1.4. • The targets for SEEV4City project are as follow: o Increase energy autonomy in SEEV4-City sites by 25%, as compared to the baseline case. o Reduce greenhouse gas emissions by 150 Tonnes annually and change to zero emission kilometres in the SEEV4-City Operational Pilots. o Avoid grid related investments (100 million Euros in 10 years) by introducing large scale adoption of smart charging and storage services and make existing electrical grids compatible with an increase in electro mobility and local renewable energy production. • The afore-mentioned objectives are achieved by applying Smart Charging (SC) and Vehicle to Grid (V2G) technologies within Operational Pilots at different levels: o Household. o Street. o Neighbourhood. o City. • SEEV4City aims to develop the concept of 'Vehicle4Energy Services' into a number of sustainable business models to integrate electric vehicles and renewable energy within a Sustainable Urban Mobility and Energy Plan (SUMEP), as introduced in Chapter 1. With this aim in mind, this project fills the gaps left by previous or currently running projects, as reviewed in Chapter 6. • The business models will be developed according to the boundaries of the six Operational Pilots, which involve a disparate number of stakeholders which will be considered within them. • Within every scale, the relevant project objectives need to be satisfied and a study is made on the Public, Social and Private Economics of Smart Charging and V2G. • In order to accomplish this work, a variety of aspects need to be investigated: o Chapter 3 provides details about revenue streams and costs for business models and Economics of Smart Charging and V2G. o Chapter 4 focuses on the definition of Energy Autonomy, the variables and the economy behind it; o Chapter 5 talks about the impacts of EV charging on the grid, how to mitigate them and offers solutions to defer grid investments; o Chapter 7 introduces a number of relevant business models and considers the Economics of Smart Charging and V2G; o Chapter 8 discusses policy frameworks, and gives insight into CO2 emissions and air pollution; o Chapter 9 defines the Data Collection approach that will be interfaced with the models; o Chapter 10 discusses the Energy model and the simulation platforms that may be used for project implementation

    Towards electric bus system: planning, operating and evaluating

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    The green transformation of public transportation is an indispensable way to achieve carbon neutrality. Governments and authorities are vigorously implementing electric bus procurement and charging infrastructure deployment programs. At this primary but urgent stage, how to reasonably plan the procurement of electric buses, how to arrange the operation of the heterogeneous fleet, and how to locate and scale the infrastructure are urgent issues to be solved. For a smooth transition to full electrification, this thesis aims to propose systematic guidance for the fleet and charging facilities, to ensure life-cycle efficiency and energy conservation from the planning to the operational phase.One of the most important issues in the operational phase is the charge scheduling for electric buses, a new issue that is not present in the conventional transit system. How to take into account the charging location and time duration in bus scheduling and not cause additional load peaks to the grid is the first issue being addressed. A charging schedule optimization model is constructed for opportunity charging with battery wear and charging costs as optimization objectives. Besides, the uncertainty in energy consumption poses new challenges to daily operations. This thesis further specifies the daily charging schedules with the consideration of energy consumption uncertainty while safeguarding the punctuality of bus services.In the context of e-mobility systems, battery sizing, charging station deployment, and bus scheduling emerge as crucial factors. Traditionally these elements have been approached and organized separately with battery sizing and charging facility deployment termed planning phase problems and bus scheduling belonging to operational phase issues. However, the integrated optimization of the three problems has advantages in terms of life-cycle costs and emissions. Therefore, a consolidated optimization model is proposed to collaboratively optimize the three problems and a life-cycle costs analysis framework is developed to examine the performance of the system from both economic and environmental aspects. To improve the attractiveness and utilization of electric public transportation resources, two new solutions have been proposed in terms of charging strategy (vehicle-to-vehicle charging) and operational efficiency (mixed-flow transport). Vehicle-to-vehicle charging allows energy to be continuously transmitted along the road, reducing reliance on the accessibility and deployment of charging facilities. Mixed flow transport mode balances the directional travel demands and facilities the parcel delivery while ensuring the punctuality and safety of passenger transport

    Energy Superhub Oxford: final report

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    Energy Superhub Oxford (ESO) is a £41m demonstration project delivering innovation in smart local energy systems. As countries around the world embark on energy transitions to decarbonise their economies, decentralised and digitised solutions are increasingly important in delivering power, heat and mobility to users. Exploring options for smart local energy systems is a key UK priority. ESO is one of three large demonstrator projects part-funded by the UK government under its “Prospering from the Energy Revolution” (PFER) programme. Work began in April 2019 and ran until March 2023. ESO’s main focus has been on investment in infrastructure for energy storage, electric vehicle charging, low carbon home heating and developing innovative, smart ways of generating benefits from these for users, investors and society at large. This report has been produced by the University of Oxford team and draws on their research findings spanning each of the major work packages: transport (including private wire and Superhub construction), decarbonising heat, and the transmission grid connected battery, its operation and carbon impact. It also includes a chapter on consortium working practices and concludes with overall learnings from the project
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