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Global warming, pollution, and increasing energy demand have compelled electrification of the transport sector. Electric vehicles are not only an attractive and cleaner mode of transport, but they also possess the capacity to offer flexible storage alternative based on bidirectional vehicle-to-grid schemes. Vehicle-to-grid or V2G technology permits electric vehicles' batteries to store energy and discharge it back to the power grid during peak-load periods. However, the feasibility and economic viability of V2G is still a matter of concern and needs investigation. In this paper, the authors delved into the feasibility of V2G technology by analysing the real time-charging data of a V2G demonstration project named EV-elocity, located at the University of Nottingham campus in the UK. The authors analysed the charging data and trip-status data of two charging sites and put forward some insights regarding the feasibility of V2G and the behavioural traits of the vehicles. This paper will enlighten the research community regarding the feasibility and benefits of V2G in a real-world environment by analysing the charging/discharging and vehicle behaviour and reporting the opportunities and benefits of vehicle-to-grid technology. [ABSTRACT FROM AUTHOR]

This paper presents the concept of using electric vehicles (EVs) as a countermeasure to deal with the negative effects of power rationing when electricity demands become difficult to meet due to unfavorable electrical system operating conditions. At present, an energy storage is widely used to maintain the stability of electricity supply in facilities whose main source of energy is renewable energy sources (RESs). However, we must not forget that electric vehicles are also electricity storage facilities, but they are not always available due to their mobility. With properly developed strategies, they can be used in electricity management processes, for example, by reducing their consumption during charging using smart charging technology, or by providing electricity from their batteries using vehicle-to-building (V2B) technology. Thus, this article presents a research methodology that treats electric vehicles as a remedy for eliminating power constraints. It consists of five main steps, including two algorithms for deciding how to deploy EVs during power rationing periods. An efficiency factor for eliminating these constraints was also introduced. The results showed that the use of smart charging or V2B technology in EVs can reduce the number of potential hours in which certain power levels are exceeded by up to several tens of percent. This means that in the future, with the significant development of electromobility, such a way of dealing with power constraints could be an alternative to conventional solutions like diesel generators. [ABSTRACT FROM AUTHOR]

The integration of renewable energy systems in buildings leads to a reduction in energy bills for end users and a reduction in the carbon footprint of such buildings, usually referred to as prosumers. In addition, the installation of charging points for the electric vehicles of people working or living in these buildings can further improve the energy efficiency of the whole system if innovative technologies, such as vehicle-to-building (V2B) technologies, are implemented. The aim of this paper is to present an Energy Management System (EMS) based on mathematical programming that has been developed to optimally manage a prosumer building equipped with photovoltaics, a micro wind turbine and several charging points for electric vehicles. Capabilities curves of renewable power plant inverters are modelled within the EMS, as well as the possibility to apply power curtailment and V2B. The use of V2B technology reduces the amount of electricity purchased from the public grid, while the use of smart inverters for the power plants allows zero reactive power to be drawn from the grid. Levelized cost of electricity (LCOE) is used to quantify curtailment costs, while penalties on reactive power absorption from the distribution network are evaluated in accordance with the current regulatory framework. Specifically, the model is applied to a prosumer building owned by the postal service in a large city in Italy. The paper reports the main results of the study and proposes a sensitivity analysis on the number of charging stations and vehicles, as well as on the consideration of different typical days characterized by different load and generation profiles. This paper also investigates how errors in forecasting energy production from renewable sources impact the optimal operation of the whole system. [ABSTRACT FROM AUTHOR]

In an electrical microgrid, distributed renewable generation is one of the main tools used to achieve energy sustainability, cost efficiency and autonomy from the grid. However, reliance on intermittent power sources will lead to a mismatch between generation and demand, causing problems for microgrid management. Flexibility is key to reducing the mismatch and providing a stable operation. In such a context, demand response and energy storage systems are the main factors that contribute to flexibility in a microgrid. This paper provides an assessment of the technical and economic impacts of a microgrid at the building level, considering photovoltaic generation, battery energy storage and the use of electric vehicles in a vehicle-to-building system. The main novel contributions of this work are the quantification of system efficiencies and the provision of insights into the design and implementation of microgrids using real on-site data. Several tests were conducted using real on-site data to calculate the overall efficiencies of the different assets during their operation. An economic assessment was carried out to evaluate the potential benefits of coordinating battery storage with a vehicle-to-building system regarding the flexibility and cost-efficient operation of the microgrid. The results show that these two systems effectively increase the levels of self-consumption and available flexibility, but the usefulness of private electric vehicles in public buildings is constrained by the schedules and parking times of the users. Furthermore, economic benefits are highly dependent on the variability of tariffs and the costs of energy storage systems and their degradation, as well as the efficiency of the equipment used in the conversion chain. [ABSTRACT FROM AUTHOR]

The renewed interest in the deployment of electric vehicles promises enhanced environmental and social compatibility, higher energy efficiency, as well as effective power grid support through the vehicle-to-grid energy exchange mode. Focusing on a smaller scale, such as buildings with large parking lots for electric vehicles, the aim of the so-called vehicle-to-building concept is to regulate the power consumption of a building by either throttling the charging rate of electric vehicles or by delivering electricity (discharging) into the building when needed. In this paper, a mathematical model is implemented in MATLAB to peak-shave and valley-fill the power consumption profile of a university building by scheduling the charging/discharging process in an electric vehicle parking lot, using real-world data of power consumption and parking lot occupancy. The simulation of three scenarios with different number of parking spots reveal the feasibility of the proposed approach to effectively flatten the power consumption profile during daytime, which is particularly important for electricity customers that the energy cost depends on the contracted power capacity. In detail, the results indicate that the peak power consumption is reduced by approximately 3% and 20% for the scenarios with the minimum and maximum number of electric vehicle parking spots respectively. [ABSTRACT FROM AUTHOR]

A two-stage hierarchical Microgrid energy management method in an office building is proposed, which considers uncertainties from renewable generation, electric load demand, outdoor temperature and solar radiation. In stage 1, a day-ahead optimal economic dispatch method is proposed to minimize the daily Microgrid operating cost, with the virtual energy storage system being dispatched as a flexible resource. In stage 2, a two-layer intra-hour adjustment methodology is proposed to smooth the power exchanges at the point of common coupling by coordinating the virtual energy storage system and the electric vehicles at two different time scales. A Vehicle-to-Building control strategy was developed to dispatch the electric vehicles as a flexible resource. Numerical studies demonstrated that the proposed method is able to reduce the daily operating cost at the day-ahead dispatch stage and smooth the fluctuations of the electric power exchanges at the intra-hour adjustment stage. [ABSTRACT FROM AUTHOR]

This article proposes a grid-interfaced solar photovoltaic-based smart building with the features of bidirectional power flow capability through electrical vehicle charging/discharging and power quality improvements at AC mains with the optimum use of involved power converters. This solar photovoltaic power generating system is also used to charge the battery of electric vehicles that are kept in the basement parking of the smart building. The electric vehicles can serve buildings as uninterruptable power supply systems. The electric vehicle batteries are charged at lean demand periods and discharged to meet peak load demand, or they are charged at peak sun periods and power can be fed back to grid at night when there is no sun availability. The electric vehicle can act as a load or distributed energy source in a bidirectional power flow mode popularly known as vehicle to grid. During daytime, the active power is either injected to the grid or stored in the storage battery of the electric vehicle. The power quality improvement for power factor correction, harmonics elimination, voltage regulation, and neutral current compensation at AC mains is achieved using the same power converter. Vehicle to grid offers reactive power compensation, active power regulation, tracking of solar photovoltaic energy, and load balancing or load leveling, further increasing efficiency and reliability of the grid. As the proposed configuration is grid interfaced, this system is also used at night when there is no sun, thus leading to optimum utilization of the power electronics involved in this configuration. [ABSTRACT FROM AUTHOR]

Energy consumption in the transport sector and buildings are of great concern. This research aims to quantify how eco-routing, eco-driving and eco-charging can increase the amount of energy available for vehicle-to-building. To do this, the working population was broken into social groups (freelancers, local workers and commuters) who reside in two cities with different climate zones (Alcalá de Henares-Spain and Jaén-Spain) since the way of using electric vehicles is different. An algorithm based on the Here® application program interface and neural networks was implemented to acquire data of the stochastic usage of EVs of each social group. Finally, an increase in the amount of energy available for vehicle-to-building was assessed thanks to the algorithm. The results per day were as follows. Owing to the algorithm proposed a reduction ranging from 0.6 kWh to 2.2 kWh was obtained depending on social groups. The proposed algorithm facilitated an increase in energy available for vehicle-to-building ranging from 13.2 kWh to 33.6 kWh depending on social groups. The results show that current charging policies are not compatible with all social groups and do not consider the renewable energy contribution to the total electricity demand. [ABSTRACT FROM AUTHOR]

Clean power production, buildings, and transportation are key areas for climate change mitigation. Their tighter integration decreases not only the emissions, but also the energy consumption of buildings and transportation. Energy integration and interactions between buildings and vehicles are dependent on the type of building, vehicle, and renewable energy system, as well as the local climatic conditions. The current academic literature does not provide a systematic analysis of this topic. In the study, different energy management systems and advanced energy control strategies have been formulated to study such interactions both from a building and a vehicle perspective. Furthermore, technical solutions have been systematically reviewed in terms of the enhancement of energy interaction capabilities, in particular from the standpoint of renewable energy systems, energy/fuel charging facilities, and control strategies. Assessment criteria employed in the review of solutions include grid interaction, annual operational cost, annual net CO 2 emissions, and annual matching capability. The literature review identifies several technical challenges that need further consideration such as capacity expansion and power fluctuation of the electric grid, low efficiency of heat recovered from electricity generation, and depreciation of vehicles. The future outlook and potential for the energy interaction networks between buildings and vehicles have also been presented. • Review of the energy integrations and interactions between buildings and vehicles. • The compatibility and feasibility of the building side to integrate the vehicles. • The readiness and flexibility of the vehicle energy systems to fit the buildings. • Review of controls which facilitate bi-directional integrations and interactions. • Future outlooks of the integrations and interactions between the two sectors. [ABSTRACT FROM AUTHOR]

• Expansion of the mobile boundary of the ZEB-Electric Vehicle (EV) interactions. • Cover the scientific gap for the past limitation of the ZEB-EV interactions. • A novel control strategy to expand the boundary to the remote parking locations. • Investigation of solutions to fully utilize the mobile storage capacities of EVs. • Impact of the V2B interactions and boundary expansion scenarios on the ZEB balance. The critical solutions to the future global target of the carbon-neutral society rely on a comprehensive and integrated consideration of both the building and transportation sectors. However, most of the past studies only considered the local interactions between the buildings and the locally-charged electric vehicles (EVs), which significantly limits the utilization of the EV storage capacities. In this study, we have investigated a hybrid photovoltaic and wind turbine supported zero-emission office building (ZEB) which is interacted with a number of electric vehicles. Furthermore, a novel control strategy, called "Boundary Expansion Scenario", has been proposed, where the boundary of the ZEB-EV interactions can be expanded from the conventional local parking to the remote parking, so that the EV batteries can be fully utilized regardless of the parking location. The impact of the renewable energy system, the Vehicle-to-Building (V2B) interactions and the boundary expansion scenarios on the zero-emission performance of the office building and the EVs have been comprehensively investigated. The research results show that by merely activating the V2B function without the "Boundary Expansion Scenario", the V2B capability can only lead to less than 5% of the enhancement of the matching capabilities, since 93.4% of the surplus renewable electricity occur mainly during the non-parking hours. However, by further activating the "Boundary Expansion Scenario", the net zero-emission system can simultaneously enable the features of the significantly enhanced matching capabilities (the OEFe and OEMe both at 62%), the much intensified building-vehicle interactions (the E B2V at 18.73 kWh/m2.a and the E V2B at 14.87 kWh/m2.a), and an almost full renewable coverage of the EV storages (the renewable energy ratio at 96.9%). [ABSTRACT FROM AUTHOR]

In the context of the increased acceptance and usage of electric vehicles (EVs), vehicle-to-building (V2B) has proven to be a new and promising use case. Although this topic is already being discussed in literature, there is still a lack of experience on how such a system, of allowing bidirectional power flows between an EV and building, will work in a residential environment. The challenge is to optimize the interplay of electrical load, photovoltaic (PV) generation, EV, and optionally a home energy storage system (HES). In total, fourteen different scenarios are explored for a German household. A two-step approach is used, which combines a computationally efficient linear optimizer with a detailed modelling of the non-linear effects on the battery. The change in battery degradation, storage system efficiency, and operating expenses (OPEX) as a result of different, unidirectional and bidirectional, EV charging schemes is examined for both an EV battery and a HES. The simulations show that optimizing unidirectional charging can improve the OPEX by 15%. The addition of V2B leads to a further 11% cost reduction, however, this corresponds with a 12% decrease in EV battery lifetime. Techno-economic analysis reveals that the V2B charging solution with no HES leads to strong self-consumption improvements (EUR 1381 savings over ten years), whereas, this charging scheme would not be justified for a residential prosumer with a HES (only EUR 160 savings). [ABSTRACT FROM AUTHOR]

Vehicle-to-building (V2B) technology permits bypassing the power grid in order to supply power to a building from electric vehicle (EV) batteries in the parking lot. This paper investigates the hypothesis stating that the increasing number of EVs on our roads can be also beneficial for making buildings sustainably greener on account of using V2B technology in conjunction with local photovoltaic (PV) generation. It is assumed that there is no local battery storage other than EVs and that the EV batteries are fully available for driving, so that the EVs batteries must be at the intended state of charge at the departure time announced by the EV driver. Our goal is to exploit the potential of the EV batteries capacity as much as possible in order to permit a large area of solar panels, so that even on sunny days all PV power can be used to supply the building needs or the EV charging at the parking lot. A system architecture and collaboration protocols that account for uncertainties in EV behaviour are proposed. The proposed approach is proven in simulation covering one year period for three locations in different climatic regions of the US, resulting in the electricity bill reductions of 15.8%, 9.1% and 4.9% for California, New Jersey and Alaska, respectively. These results are compared to state-of-the-art research in combining V2B with PV or wind power generation. It is concluded that the achieved electricity bill reductions are superior to the state-of-the-art, because previous work is based on problem formulations that exploit only a part of the potential EV battery capacity. [ABSTRACT FROM AUTHOR]