Price effect analysis and pre-reseravtion scheme on electric vehicle charging networks

This paper investigates the price effect to the charging demand coming from electric vehicles and then evaluates the performance of a pre-reservation mechanism using the real-life demand patterns. On the charging network in Jeju city, the occupancy rates for 3 price groups, namely, free, medium-price, and expensive chargers, are separated almost evenly by about 9.0 %, while a set of chargers dominates the charging demand during hot hours. The virtual pre-reservation scheme matches electric vehicles to a time slot of a charger so as not only to avoid intolerable waiting time in charging stations systematically but also to increase the revenue of service providers, taking into account both bidding levels specified by electric vehicles and preference criteria defined by chargers. The performance analysis results obtained by prototype implementation show that the proposed pre-reservation mechanism improves the revenue of service providers by up to 9.5 % and 42.9 %, compared with the legacy FCFS and reservation-less walk-in schemes for the given performance parameter sets

Renewable energy allocation based on maximum flow modelling within a microgrid

This paper designs an energy allocation scheme based on maximum flow modeling for a microgrid containing renewable energy generators and consumer facilities. Basically, the flow graph consists of a set of nodes representing consumers or generators as well as a set of weighted links representing the amount of energy generation, consumer-side demand, and transmission cable capacity. The main idea lies in that a special node is added to account for the interaction with the main grid and that two-pass allocation is executed. In the first pass, the maximum flow solver decides the amount of the insufficiency and thus how much to purchase from the main grid. The second pass runs the flow solver again to fill the energy lack and calculates the surplus of renewable energy generation. The performance measurement result obtained from a prototype implementation shows that the generated energy is stably distributed over multiple consumers until the energy generation reaches the maximum link capacity

Spatial-temporal domain charging optimization and charging scenario iteration for EV

Environmental problems have become increasingly serious around the world. With lower carbon emissions, Electric Vehicles (EVs) have been utilized on a large scale over the past few years. However, EVs are limited by battery capacity and require frequent charging. Currently, EVs suffer from long charging time and charging congestion. Therefore, EV charging optimization is vital to ensure drivers’ mobility. This study first presents a literature analysis of the current charging modes taxonomy to elucidate the advantages and disadvantages of different charging modes. In specific optimization, under plug-in charging mode, an Urgency First Charging (UFC) scheduling policy is proposed with collaborative optimization of the spatialtemporal domain. The UFC policy allows those EVs with charging urgency to get preempted charging services. As conventional plug-in charging mode is limited by the deployment of Charging Stations (CSs), this study further introduces and optimizes Vehicle-to-Vehicle (V2V) charging. This is aim to maximize the utilization of charging infrastructures and to balance the grid load. This proposed reservation-based V2V charging scheme optimizes pair matching of EVs based on minimized distance. Meanwhile, this V2V scheme allows more EVs get fully charged via minimized waiting time based parking lot allocation. Constrained by shortcomings (rigid location of CSs and slow charging power under V2V converters), a single charging mode can hardly meet a large number of parallel charging requests. Thus, this study further proposes a hybrid charging mode. This mode is to utilize the advantages of plug-in and V2V modes to alleviate the pressure on the grid. Finally, this study addresses the potential problems of EV charging with a view to further optimizing EV charging in subsequent studies

Proceedings of the Second International Mobile Satellite Conference (IMSC 1990)

Presented here are the proceedings of the Second International Mobile Satellite Conference (IMSC), held June 17-20, 1990 in Ottawa, Canada. Topics covered include future mobile satellite communications concepts, aeronautical applications, modulation and coding, propagation and experimental systems, mobile terminal equipment, network architecture and control, regulatory and policy considerations, vehicle antennas, and speech compression

Intermediation in Future Energy Markets: Innovative Product Design and Pricing

In order to mitigate the impacts of climate change, the international community envisages significant investments in electricity generation from renewable energy sources (RES). The integration of this decentralized and fluctuating type electricity generation poses several challenges to planning, operation, and economics of power systems. The established energy systems were originally designed for a centralized electricity generation that follows the uncontrolled but well predictable demand. However, for large shares of RES, relying only on the flexibility of the generation side would be economically inefficient. Furthermore, the environmental benefits of using RES would be depleted by additional carbon emissions from ramping highly flexible fossil-fueled power plants. An appealing alternative to facilitate the efficient integration of large shares of RES is to exploit the so far mainly passive demand side as an additional source of flexibility. The established centralized approaches can hardly handle the fine-grained and decentralized nature of demand side flexibility. Therefore, the intermediation between centralized control and decentralized demand will play a major role in future energy markets, which constitutes the overarching topic of this dissertation. Typically electricity generation from RES is capital-intensive but has near zero marginal costs. On this account, novel services need to be offered in order to transmit the right economic signals. To this end, the concept of the differentiable good electricity is refined in this dissertation. Embedded into the so-called energy service, characteristics such as temporal and spatial price differentiation or the risk of interruption can be specified to differentiate the so far homogeneous good. Based on the morphological design theory a framework for the notion of energy services is established and subsequently implemented as a decision support system. This supports a systematic and structured product development process to design innovative energy services. Such an innovative energy service is, e.g., the charging of electric vehicles in car parks, where prices are differentiated by job completion deadline. This allows the car park operator to control the aggregated load of all charging jobs to follow local RES generation. Based on this energy service the downstream activity of an intermediary is formally modeled as an optimization problem and evaluated by means of an empirical simulation experiment. The results provide insights on pricing policy and the value of demand side flexibility with regard to both the integration of local RES generation and operative profit optimization. In order to illustrate another innovative energy service the presented model is extended by the upstream activity of the intermediary. Household consumers are offered monetary incentives if they allow the intermediary to control their appliances. The results indicate the cost saving potential from demand side flexibility for the intermediary\u27s procurement of electricity. Beyond that, this model formulation constitutes the foundation for further examinations, e.g., to study the strategic behavior of intermediaries on real-time electricity markets that are prone to market power abuse due to low market liquidity

Inside the Politics of Technology

Man is the measure of all things, an old saying goes. But it is a bad guide for understanding scientific and technological culture. Science and technology are not simply the means to reach human ends; they also actively shape human beings, their goals, meanings and social relations. This volume discusses the implications of this so-called 'co-production' of science, technology and society for our analytical as well as normative ideas about humanity, technology and the relations between both. Addressing issues such as cancer genetics, prenatal screening and ecological consequences of traffic and transport, contributors argue that technology has its own kind of sub-politics, which in turn calls for policies of technology: from steering and regulation to scenario studies, in order to achieve democratisation of technology

The World Is Upside Down : Women\u27s Participation in Religious Movements in Mozambique

In recent years, new Pentecostal-style churches have proliferated around the world. Expanding at astonishing rates in Africa, Latin America, and Asia, the growth of Pentecostal-Charismatic Churches has shifted the global center of gravity of Christianity from the West to the global South. This dissertation takes a new approach to studying the impacts of such powerful new religious developments. Rather than study a single type of religious group, the study follows women, the striking majority of participants in Pentecostal churches and in emergent forms of “traditional” religion, through new networks of spiritual healing. Drawing on over ten years of personal connections and more than three years of ethnographic field research in central Mozambique, this dissertation examines the dynamics of these religious developments in the lives of women participants, providing a view into how larger forces associated with globalization differentially impact women. Central to the dissertation is an illustration of how, through participation in new networks of religious and spiritual healing, women are creating and adopting new strategies to cope with increasing strain in their daily lives