Vehicle-to-grid

Vehicle-to-grid (V2G) describes a system in which power can be sold to the electrical power grid by an electric-drive motor vehicle that is connected to the grid when it is not in use for transportation. cite book
last =Cleveland
first =Cutler J.
coauthors =Morris, Christopher
year =2006
title =Dictionary of Energy
publisher =
location =
id =
isbn =0080445780 Page 473. ] Alternatively, when the car batteries need to be fully charged, the flow can be reversed and electricity can be drawn from the electrical power grid to charge the battery.

Vehicle-to-grid can be used with such "gridable" vehicles, this is, "pluginable" vehicles as Battery Electric Vehicles (BEV) or Plug-in hybrid electric vehicles (PHEV), with grid capacity. Since most vehicles are parked an average of 95 percent of the time, their batteries could be used to let electricity flow from the car to the power lines and back, with a value to the utilities of up to $4,000 per year per car. Since power companies only buy power in blocks of 1 MW, at least 20,000 vehicles need to be connected to the grid.cite web
year = 2007 | month = December 9| title = Car Prototype Generates Electricity, And Cash
work = Science Daily
url =http://www.sciencedaily.com/releases/2007/12/071203133532.htm
accessdate=2007-12-05]

Many various V2G projects are going on throughout the USA. Notably, at the University of Delaware, a V2G team headed by Dr. Willett Kempton has been conducting on-going research. Their goals are to educate about the environmental and economic benefits of V2G and enhance the product market.cite journal
first =Jim
last =Motavalli
year = 2007
month = September 2
title =Power to the People: Run Your House on a Prius
journal = New York Times
url = http://www.nytimes.com/2007/09/02/automobiles/02POWER.html] cite web
url =http://www.udel.edu/V2G
accessdate=2008-2-5
year = 2001
month = June
title = V2G : Vehicle to Grid Power
url = http://www.udel.edu/V2G]

History

The company AC Propulsion Inc. coined the term V2G for vehicle-to-grid. cite book
last =Emadi
first = Ali
year = 2005
title =Handbook of Automotive Power Electronics and Motor Drives - Page 34
publisher =
location =
id =Page 34 ]

Three versions

V2G is a version of Battery-to-grid power applied to vehicles. There are three different versions of the vehicle-to-grid concept:

*A hybrid or Fuel cell vehicle, which generates power from storable fuel, uses its generator to produce power for a utility at peak electricity usage times. Here the vehicles serve as a distributed generation system, producing power from conventional fossil fuels.
*A battery-powered or hybrid vehicle which uses its excess rechargeable battery capacity to provide power to the electric grid during peak load times. These vehicles can then be recharged during off-peak hours at cheaper rates while helping to absorb excess night time generation. Here the vehicles serve as a distributed battery storage system to buffer power.
*A solar vehicle which uses its excess charging capacity to provide power to the electric grid when the battery is fully charged. Here the vehicle effectively becomes a small renewable energy power station. Such systems have been in use since the 1990s and are routinely used in the case of large vehicles, especially solar-powered boats.

Peak load leveling

The concept allows V2G vehicles to provide power to help balance loads by "valley filling" (charging at night when demand is low) and "peak shaving" (sending power back to the grid when demand is high). It can enable utilities new ways to provide regulation services (keeping voltage and frequency stable) and provide spinning reserves (meet sudden demands for power). In future development, it has been proposed that such use of electric vehicles could buffer renewable power sources such as wind power, for example, by storing excess energy produced during windy periods and providing it back to the grid during high load periods, thus effectively stabilizing the unreliable nature of wind power. Some see this application of vehicle-to-grid technology as a renewable energy approach that can penetrate the baseline electric market.

It has been proposed that public utilities would not have to build as many natural gas or coal-fired power plants to meet peak demand or as an insurance policy against blackoutsWoody, Todd. [http://blogs.business2.com/greenwombat/2007/06/photo_green_wom.html "PG&E's Battery Power Plans Could Jump Start Electric Car Market."] (Blog). "Green Wombat", 2007-06-12. Retrieved on 2007-08-19.] Since demand can be measured locally by a simple frequency measurement, dynamic load leveling can be provided as needed. [ [http://www.freepatentsonline.com/4317049.html Frequency adaptive, power-energy re-scheduler] (Patent)]

Backup power solutions

V2G could also be used as a buffer during power outages. However, at the present time many electric vehicle conversion owners, whose battery of choice is still lead acid with limited cycle lives and capacity, would prefer to use them to power their cars rather than load-balance the electricity grid.

As the "New York Times" explains:

Future battery developments cite web
year =2005 | month =March 29
title =Toshiba's New Rechargeable Lithium-Ion Battery Recharges in Only One Minute
work =Toshiba Corporation | url = http://www.toshiba.co.jp/about/press/2005_03/pr2901.htm
accessdate=2007-12-05 (Press release) ] may change the economic equation, making it advantageous to use newer high capacity and longer-lived batteries in BEV/PHEVs and in grid load balancing and as a large energy cache for renewable grid resources. Even if cycled daily, such batteries would only require replacement/recycling every 55 years or so. Since BEVs can have up to 50 kWh worth of battery storage they represent somewhat more than the average homes daily energy demand. Even without a PHEV's gas generation capabilities such a vehicle could be utilized for emergency power for several days (V2H or Vehicle-to-home). As such they may be seen as a complementary technology for intermittent renewable power resources such as wind or solar electric.Fact|date=December 2007

Utilities

These utilities currently have V2G technology trials:
*PG&E, USA, converting a number of company-owned Toyota Prius to be V2G PHEVs at Google's campus
*Xcel Energy, USA, converting six Ford Escape Hybrids to PHEVs with V2G

kepticism

There is some skepticism among experts about the feasibility of V2G. As the New York Times states:

A Environmental Defense representative stated: "It’s hard to take seriously the promises made for plug-in hybrids with 30-mile all-electric range or any serious V2G application any time soon. It’s still in the science project stage."

The Vehicle-to-grid potential of Honda’s full hybrid vehicles is unexplored, but Honda is doubtful of using them to power homes. "We would not like to see stresses on the battery pack caused by putting it through cycles it wasn’t designed for," said a Honda spokesman. "Instead, they should buy a Honda generator that was made for that purpose."

Not all skepticism is warranted. Federal Energy Regulatory Commissioner Jon Wellinghoff points out that it is a myth that vehicle to grid necessarily decreases the life of the battery. When V2G is used to fill valleys of demand, it stabilizes the grid by absorbing surges in capacity. This can be done "without affecting the charge whatsoever." ["Plug-in Electric Vehicles 2008: What Role for Washington" Conference transcript, page 347, hosted by Brookings Institution and Google.org on 11-12 June 2008 [http://www.brookings.edu/~/media/Files/events/2008/0611_plugin_vehicles/0611_plugin_vehicle.pdf] ]

See also

* Charge Control
* Charging station
* Distributed generation
* Electranet
* Electrical substation
* Electricity meter
* Energy demand management
* Feed-in Tariff
* Grid energy storage
* Grid-tied electrical system
* Inverter (electrical)
* Load profile
* Operating reserve
* Peaking power plant
* Power outage
* Small is Profitable
* Smart meter

References

External links

*cite journal
first = Stephen
last = Diehl
year =
month =
title = Study suggests electric cars could pay their owners back
journal = Green Mountain College
url = http://www.greenmtn.edu/news/V2G.asp
format = Dead link|date=May 2008
*cite journal
first = Willett
last =Kempton
year =2005
month =6 June
title = Automobiles: Designing the 21st century fleet
journal = Seattle V2G Technical Symposium, University of Delaware
url = http://www.sustainableballard.org/ev2g/pdf/Kempton-V2G-Designing-June05.pdf [PDF]
*cite journal
first =Terry
last =Penney
coauthors =Jennifer Elling
year = 2005
month =August
title =The Race to Connect Cars, Communities and Renewables
journal = Geotimes.org
url =http://www.geotimes.org/aug05/feature_pluginhybrid.html
*cite journal
first =Todd
last =Woody
year = 2007
month = June 12
title = PG&E's Battery Power Plans Could Jump Start Electric Car Market
journal = Blogs.business2.com
url = http://blogs.business2.com/greenwombat/2007/06/photo_green_wom.html
format =dead link|date=September 2008 – ^{[http://scholar.google.co.uk/scholar?hl=en&lr=&q=author%3AWoody+intitle%3APG%26E%27s+Battery+Power+Plans+Could+Jump+Start+Electric+Car+Market&as_publication=blogs.business2.com&as_ylo=2007&as_yhi=2007&btnG=Search Scholar search]}
*cite journal
first =Jim
last = Woolsey
coauthors = Sexton, Chelsea; Brilliant, Larry
year =
month =
title = RechargIT: Plug-in Hybrids and V2G
journal = Youtube.com
url =http://www.youtube.com/watch?v=oDjSbWTJbdo

*cite journal
year =
month = March 3
title = 20kW DC/AC Power Inverter Preliminary Specifications, For Distributed Power Applications
journal = UQM Technologies, Inc.
url = http://www.uqm.com/products/specsheets/Power%20Inverter.html
format = dead link|date=June 2008 – ^{[http://scholar.google.co.uk/scholar?hl=en&lr=&q=intitle%3A20kW+DC%2FAC+Power+Inverter+Preliminary+Specifications%2C+For+Distributed+Power+Applications&as_publication=UQM+Technologies%2C+Inc.&as_ylo=&as_yhi=&btnG=Search Scholar search]}
*cite web
title =Electric Drive Transportation Association
work = EDTA
url =http://www.evaa.org/
accessdate=2007-10-05
*cite journal
first =
last =
year =
month =
title = Electrifying Times Magazine, Latest Electric Car News
journal =Electrifying Times Magazine
url = http://www.electrifyingtimes.com/
*cite web
title = EV World
work = EV World
url = http://evworld.com/
accessdate=2007-10-05 "Welcome to EV World, online since 1998. We invite you to explore the fascinating world of sustainable transportation technologies, the energy that powers it and the people who are making it happen."
*cite web
title = Hybrid Center
work = Union of Concerned Scientists
url = http://www.hybridcenter.org/
accessdate=2007-10-05
*cite web
title = Real Hybrid Mileage Database
work =Green Hybrid
url = http://www.greenhybrid.com/
accessdate=2007-10-05
*cite journal
first =
last =
year =
month =
title =Reports, Papers, and Presentations
journal = AC Propulsion Inc.
url = http://www.acpropulsion.com/resources/reports.htm
isbn =0750646365
*cite journal
first =
last =
year =
month =
title =V2G: Vehicle to Grid Power
journal = University of Delaware research program
url = http://www.udel.edu/V2G/
doi =10.1016/j.jpowsour.2004.12.025.
doi_brokendate =2008-06-23
*cite web
title =V2Green
work =
url =http://www.v2green.com/
accessdate=2007-10-05 Company promoting v2G technology.
*cite web
year =2007
month =October 22
title =World's First V2G Demo
work =The California Cars Initiative
url =http://www.calcars.org/calcars-news/862.html
accessdate=2007-10-05

Related forums
*cite web
title = gridable-hybrids
work =autos.groups.yahoo.com
url =http://autos.groups.yahoo.com/group/gridable-hybrids/
accessdate=2007-10-05
*cite web
title = priusplus
work =autos.groups.yahoo.com
url =http://autos.groups.yahoo.com/group/priusplus/messages
accessdate=2007-10-05
*cite web
title = Calcars
work =groups.yahoo.com
url =http://groups.yahoo.com/group/calcars-news/messages
accessdate=2007-10-05