An Overview of V2G Technology in the Development of Sustainable Electric Energy Systems

An Overview of V2G Technology in the Development of Sustainable Electric Energy Systems

Abstract–To address the utilization and management of electricity using Plug-in (Hybrid) Electric Vehicles (P(H)EVs) so that we can achieve our maximum potentials. In order to reduce fuel cost and oil dependency, this paper describes the basic structure about Vehicle to Grid (V2G) technology and how we can use this technology to reduce green house gases. Vehicle-to-grid (V2G) technology describes a system in which power is sold to the utility by grid connected P(H)EV’s electric-drive motor or battery storage or both. Alternatively, when the car batteries need charging, the power flow is reversed and electricity from the power grid is used to charge the battery. V2G allows EVs to provide energy and/or services to the grid, through an aggregator, for compensation

Index Terms –V2G technology, energy management, sustainable energy system, PHEV, PEV, smart grid.

I. Introduction

For over 100 years coal and fossil fuels have been used by power plants to produce the electricity used every day. The grid is a network of power line and substation that carrying electricity from power plants to homes and industries. Today the grid has problems, it needs updating its running capacity. When power line breaks or power plants can’t produce enough power, blackout can occur.

At the same time, today’s grid often relies on a single power source and does not provide detailed information of usage which makes difficult to manage electricity. To address these problems in past we simply build new power plants but now we are working on sustainability and reduce our dependent on fossil fuel.

To meet the requirement of an additional energy by using different technologies has always been a matter of great concern. As renewable energy technologies have variable control outputs so that it needs to make stable. One such way to reduce peak load and to keep voltage and frequency being stable is implementing Vehicle to Grid technology (V2G) using Plug-In Hybrid Electric Vehicles (P(H)EV’s). (P(H)EV’s) not only provide an excellent and efficient mean of transportation but also improve an environmental impact of green house gases. We can also implement smart grid technology for two way communications between utilities and customers to manage greater efficiency and stability in electric grids.

II. Related work

AC Propulsion [1] developed the first Vehicle to Grid (V2G) capable electric vehicle in the world. One of tzero™ technology's most attractive and unique features is the integrated 20-kW bi-directional grid power interface. With bi-directional capability, many new applications are opened up for electric drive vehicles of all types, including distributed generation, selling grid ancillary services, automated battery diagnostic discharge testing, and using vehicles to provide uninterruptible backup power to homes or businesses. With Grid technology enabling consumers greater access to solar and wind power, AC's tzero™ technology will play a vital role in regulating and stabilizing the grid, as well as buffering the natural variations in power output from huge solar and wind power installations.

Pacific Gas and Electric Company [2] showcased the first-ever utility Vehicle-to-Grid (V2G) technology demonstration. The demonstration marks a milestone in the development of innovative technologies to make electric vehicles suppliers of electricity to homes and businesses. Pacific Gas and Electric Company (PG&E) and BMW are working together to test the ability of EV batteries to provide services to the electrical grid [3].

According to an IBM press release [4], the company just announced it has teamed up with American Honda Motor Co., Inc. and Pacific Gas and Electric Company, PG&E in order to facilitate a new pilot project for a smarter communication means between electric vehicles, EVs and our power grid.

Xcel Energy [5] announces six plug-in hybrid electric vehicles (PHEVs) will be on the road by the end of 2007 as part of a demonstration test of vehicle-to-grid (V2G) technology by Xcel Energy. The project, which will convert six Ford Escape Hybrids to PHEVs equipped with V2G technology so each can charge and discharge power to and from the grid, is one of the nation’s first real-world demonstrations of the V2G technology.

NREL's [6] electric vehicle grid integration work supports the development and implementation of electrified transportation systems, particularly those that integrate renewable-based vehicle charging systems. Plug-in electric vehicles (PEVs)—including all-electric vehicles and plug-in hybrid electric vehicles—offer the opportunity to shift transportation energy demands from petroleum to electricity, but broad adoption will require integration with other energy systems.

III. Objectives

The main objective of this paper is to discuss the issues of electricity generation, storage and transmission and how we can solve these issues with the help of smart grid and V2G technology. Let’s say a tree falls on a power line and one thousand homes loose power. With a current grid you turn to be unpleased, often physically to redraw power which takes time. With the smart grid, sensors and softwares you will detect and immediately reroute the power around the problem with in a limited time. If the price of electricity changes throughout the day, we can see it with a current meter on our homes. It may be expensive in peak hours and cheap in late night. With new smart meters at our homes we can use air conditioner when the price is cheap. This provides more control on energy bill and helps to prevents black out at peak hours.

The smarter grids also mean a new ways to use renewable energy. Power generation can now be distributed across multiple sources, so the system is more stable and efficient. It has an ability to communicate and manage electricity that makes grid smarter and helps us to avoid burning more fossil fuels in the future.

The necessary components which we need to make smart grids are:

1. Smart Meters
2. Phasor Measurement Unit
3. Information transfer (like Zigbee)
4. Distributed Generation

IV. Electric Vehicle

There are some developments that have changed our life permanently. Developments without which an everyday life is simply no longer imaginable and there are some development that changes our life style so fast. One of them is an electric vehicle (EVs). It is an excellent mean of transportation.

EVs are still equipped with an internal combustion engine but now with hybrid drive system. Vehicle designs are changing faster than our expectations. The reason for these developments is global changes and major economic markets that urgently demand new concepts, but how important a new vehicle concept? One thing that certain is to turn a total electrification of the vehicle; there is no question about that. This is the real opportunity for enterprises specializing in the electrical system and electronics.

Currently vehicle equipped with petrol and diesel engine adds up to 25% of the world’s CO₂ emissions. But EVs are powered by electricity rather than fuel, which mean that they do not produce any CO₂ emissions. CO₂ contributes to the greenhouse effect and is known as the “most important long-lived “forcing” of climate change”. The greenhouse effect is when the atmosphere traps heat which leads to an increase in the temperature on the surface.

Electric Vehicles could give power back to the grid using V2G technology. For this a tremendous investments will be needed to reinforce the grid and to introduce charging facilities.

To make an electric vehicle V2G capable, each vehicle will be equipped with a V2G Connectivity Module that not only controls vehicle charging but also collects data and communicates between utility and a vehicle owner. It also contain a several kilowatt (such as 10kW) inverter, motor and charger equipped with electric vehicle. V2G will also supply server software enabling remote control of smart charging and V2G functions so that we can control the battery cycles by remotely in case of receiving a message of postpones the charging by the main grid due to less availability of power.

An electric vehicle can also charge wirelessly by means of resonators. The wireless power transfer is based on a technology called magnetic resonance coupling. Two copper coils are tuned to resonate at the same natural frequency – like two wine glasses that vibrate when a specific note is sung. The coils are placed a few feet apart. One coil is connected to an electric current, which generates amagnetic fieldthat causes the second coil to resonate. This magnetic resonance results in the invisible transfer of electric energy through the air from the first coil to the receiving coil. [8]

Plug-in hybrid electric vehicles can also generate power by means of regenerative braking system, in which we can convert kinetic energy in the form of electricity and store it in storage batteries because electric vehicles always rely on rechargeable batteries for power.

[7]

V. Vehicle To Grid Technology

In near future the number of electric vehicles may increase on roads which seem to be unnecessary burden over an electric grid but we have a solution in which electric drive vehicles plays a major role as a part of power grid operation and will provide valued services. The peaking power plants operate for a short period but it needs heavy investments when the required demand is not fulfill by an existing grid. For this we have a V2G technology to reduce the need to invest heavily in peaking power plants and storage.

Here an electric vehicle battery serves as a storage device which transfers its power to the grid when there is a peak shaving. As tens of thousands or hundred of thousand of electric vehicle are connecting to the electric power systems we then looking at these vehicles since none only charging from the grid but also providing power back to the grid for periods of emergencies or during regular operations to maintain reliability of the power systems.

For a long term by we are looking these grid connected vehicles for providing storage for renewable resources such as wind and solar. You can later charging the plug-in electric vehicles in evening or early morning hours that the electric grids can support hundreds of thousands of electric vehicles by means of wind energy and then it return back to the grid when it is not in use for transportation so we do not need to purchase or build new power plants. The control signal from the grid operator could be a broadcast radio signal, a cell phone network, or power line carrier. The grid operator sends requests for power to a large number of vehicles. The signal may go directly to each individual vehicle, to a fleet operator, or through a third-party aggregator to dispatch power from individual vehicles. [9]

The markets now also have huge decentralized mobile energy storage system available that will effect global energy trading. Electric grids have to move the way from the top down principal towards on bi-directional interacting with smart grids. Serial integration in the smart grids will allow maximum efficiency and sustainability keeps down energy cost for consumers and at the same time significantly improve grid stability.

New smart interfaces will change the energy market, individual mobility will be guaranteed at all time. Total electrification of the vehicle lead a new kind of architecture of the vehicle with plenty of options; renew functions in the vehicle and going towards better environment.

VI. V2G Pictorial View

VII. Strategies To Implement V2G

To develop a V2G Technology we must ensures smooth functioning of the system by providing the following necessary operations:

1. Tremendous investments will be needed to reinforce the grid and to introduce charging facilities.
2. Plan to build smart charging systems at various places.
3. Plan to build smart communication between utilities and EV owners.
4. Motivate manufacture of (P(H)EVs) with acceptable cost.
5. Motivate battery manufacturers for cost effective V2G storage.
6. Motivate Independent Power Produces toward implementation

VIII. Conclusion & Future Enhancements

Acknowledgment

References

[1] Acpropulsion.com, 'AC Propulsion | Creating electric vehicles that people want to drive', 2015. [Online]. Available: https://www.acpropulsion.com/faqs.html.

[2]P. Company, 'Pacific Gas and Electric Company Energizes Silicon Valley With Vehicle-to-Grid Technology', Prnewswire.com, 2015. [Online]. Available: http://www.prnewswire.com/news-releases/pacific-gas-and-electric-company-energizes-silicon-valley-with-vehicle-to-grid-technology-57952787.html.

[3]C. Morris, 'Charged EVs | PG&E and BMW team up to test V2G services', Chargedevs.com, 2015. [Online]. Available: http://chargedevs.com/newswire/pge-and-bmw-team-up-to-test-v2g-services/.

[4] Torquenews.com, 'IBM, Honda and Pacific Gas and Electric Company Team Up For A Smart Grid - Torque News', 2015. [Online]. Available: http://www.torquenews.com/1079/ibm-honda-and-pacific-gas-and-electric-company-team-smart-grid.

[5]B. Media, 'Green Car Congress: Xcel Energy Announces Six-Month Test of V2G and Plug-In Hybrid Electric Vehicles', Greencarcongress.com, 2015. [Online]. Available: http://www.greencarcongress.com/2007/10/xcel-energy-ann.html.

[6] Nrel.gov, 'NREL: Transportation Research - Electric Vehicle Grid Integration', 2015. [Online]. Available: http://www.nrel.gov/transportation/project_ev_grid_integration.html.

[7] Animationoptions.com, 'Plug In Hybrid Electric Vehicle', 2015. [Online]. Available: http://www.animationoptions.com/photobphi/plug-in-hybrid-electric-vehicle.

[8] Phys.org, 'Wireless power could revolutionize highway transportation, researchers say', 2015. [Online]. Available: http://phys.org/news/2012-02-wireless-power-revolutionize-highway.html.

[9] Google Books, 'Patent US20070282495 - System and method for assessing vehicle to grid (v2g) integration', 2015. [Online]. Available: http://www.google.com.pk/patents/US20070282495.