View source for Vehicle-to-grid

{{Short description|Vehicle charging system that allows discharge and storage of electricity}}
{{Use dmy dates |cs1-dates=y |date=January 2023}}
[[File:V2GEnabledEVFastCharger.jpg|thumb|A V2G-enabled EV fast [[charging station]].]]

'''Vehicle-to-grid''' ('''V2G''') describes a system in which [[plug-in electric vehicle]]s (PEVs) sell [[demand response]] services to the [[Electrical grid|grid]]. Demand services are either delivering electricity to the grid or reducing the rate of charge from the grid. Demand services reduce the peaks in demand for grid supply, and hence reduce the probability of disruption from load variations.<ref name="dictionary">{{cite book |last1=Cleveland |first1=Cutler J. |last2=Morris |first2=Christopher |year=2006 |title=Dictionary of Energy |publisher=Elsevier |location=Amsterdam |isbn=978-0-08-044578-6 |page=[https://archive.org/details/dictionaryofener00amst/page/473 473] |url-access=registration |url=https://archive.org/details/dictionaryofener00amst/page/473 }}</ref><ref>{{cite web |url = http://www.pge.com/about/news/mediarelations/newsreleases/q2_2007/070409.shtml |title = Pacific Gas and Electric Company Energizes Silicon Valley With Vehicle-to-Grid Technology |date = 2007-04-07 |access-date = 2009-10-02 |publisher = Pacific Gas & Electric |url-status = dead |archive-url = https://web.archive.org/web/20091209122555/http://www.pge.com/about/news/mediarelations/newsreleases/q2_2007/070409.shtml
 |archive-date = 2009-12-09 }}</ref><ref name="AppliedEnergy">{{Cite journal|last1=Robledo|first1=Carla B.|last2=Oldenbroek|first2=Vincent|last3=Abbruzzese|first3=Francesca|last4=Wijk|first4=Ad J.M. van|title=Integrating a hydrogen fuel cell electric vehicle with vehicle-to-grid technology, photovoltaic power and a residential building|journal=Applied Energy|volume=215|pages=615–629|doi=10.1016/j.apenergy.2018.02.038|year=2018|s2cid=115673601 |url=https://repository.tudelft.nl/islandora/object/uuid%3A91672947-add6-4bdd-8b90-8d9d12d00fed/datastream/OBJ/download|doi-access=free|bibcode=2018ApEn..215..615R }}</ref>  '''Vehicle-to-load''' ('''V2L''') and '''Vehicle-to-vehicle''' ('''V2V''') are related, but the AC phase is not synchronised with the grid, so the power is only available to "off-grid" load.

Plug-in electric vehicles include [[battery electric vehicle]]s (BEVs), [[plug-in hybrid]]s (PHEVs), and [[hydrogen vehicle]]s. They share the ability to generate electricity which is typically used to power the vehicle. However, because cars spend most of the time parked, their energy remains stored. V2G allows some of this stored power to be sent to the grid, and reduces the need to take power from the grid. A 2015 report found that vehicle owners could receive significant payments by charging their EVs at off-peak times when electricity is cheaper, storing it in their car battery, and selling it back to the grid at peak times when electricity prices are higher.<ref>{{Cite journal|last1=He|first1=Y.|last2=Bhavsar|first2=P.|last3=Chowdhury|first3=M.|last4=Li|first4=Z.|date=2015-10-01|title=Optimizing the performance of vehicle-to-grid (V2G) enabled battery electric vehicles through a smart charge scheduling model|journal=International Journal of Automotive Technology|volume=16|issue=5|pages=827–837|doi=10.1007/s12239-015-0085-3|s2cid=38215809|issn=1976-3832}}</ref>

Batteries have a finite number of charging cycles, as well as a limited shelf-life, so V2G can reduce battery longevity. Battery capacity is a complex function of battery chemistry, charge/discharge rates, temperature, state of charge and age, but is improving as technology improves. Most studies of the effects of V2G on battery life show that slower V2G discharge rates lessen degradation, while one study suggested that using vehicles for grid storage could improve longevity.<ref>{{cite journal |last1=Uddin |first1=Kotub |last2=Jackson |first2=Tim |last3=Widanage |first3=Widanalage D. |last4=Chouchelamane |first4=Gael |last5=Jennings |first5=Paul A. |last6=Marco |first6=James |title=On the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system |journal=Energy |date=August 2017 |volume=133 |pages=710–722 |doi=10.1016/j.energy.2017.04.116 |doi-access=free |bibcode=2017Ene...133..710U }}</ref>

Hydrogen [[fuel cell vehicle]]s (FCV) with tanks containing 5.6&nbsp;kg of hydrogen can deliver more than 90 kWh of electricity.<ref name="tudelft">{{Cite web |last=Wassink |first=Jos |date=2016-07-18 |title=Hydrogen car as power backup |url=https://www.delta.tudelft.nl/article/hydrogen-car-power-backup |access-date=2017-11-07 |website=Delta TU Delft}}</ref> Vehicle batteries may hold [[BMW iX|100 kWh or more]].

Uni-directional V2G (UV2G) charging is technically simpler than delivering power from an EV battery, which many PEVs are not equipped to do.<ref>{{Cite journal|last1=Chukwu|first1=Uwakwe C.|last2=Mahajan |first2=Satish M.|title=V2G parking lot with PV rooftop for capacity enhancement of a distribution system|journal=IEEE Transactions on Sustainable Energy |date=2014 |volume=5|issue=1|pages=119–127|doi=10.1109/TSTE.2013.2274601 |bibcode=2014ITSE....5..119C |s2cid=33198534 }}</ref> {{As of|2024}}, most EVs require a separate inverter than the one used to power the propulsion motors in order to output AC power from the battery. UV2G can be extended by throttling other activities such as air heating and cooling.<ref>{{cite journal | last1 = Yong | first1 = Jia Ying | display-authors = etal | year = 2015 | title = A review on the state-of-the-art technologies of electric vehicle, its impacts and prospects | journal = Renewable and Sustainable Energy Reviews | volume = 49 | pages = 365–385 | doi = 10.1016/j.rser.2015.04.130 | bibcode = 2015RSERv..49..365Y }}</ref><ref>{{cite journal | last1 = Sortomme | first1 = Eric | last2 = El-Sharkawi | first2 = Mohamed | year = 2011 | title = Optimal charging strategies for unidirectional vehicle-to-grid | journal = Smart Grid, IEEE Transactions on | volume = 2 | issue = 1| pages = 131–138 | doi = 10.1109/tsg.2010.2090910 | s2cid = 9522962 }}</ref>

==History==
V2G began as vehicle-to-vehicle (V2V) charging, as introduced by California company AC Propulsion in the early 1990s. Their two-seater Tzero car featured two-way charging.<ref>{{Cite web |last=Goldstein |first=Harry |date=2022-08-01 |title=What V2G Tells Us About EVs and the Grid |url=https://spectrum.ieee.org/what-v2g-tells-us-about-evs-and-the-grid-2657785771 |access-date=2022-08-16 |website=IEEE Spectrum |language=en}}</ref> V2G allows charging and discharging between vehicle and grid.<ref>{{Cite web |title=Vehicle-to-Grid (V2G): Everything you need to know |url=https://www.virta.global/vehicle-to-grid-v2g |access-date=2022-11-11 |website=Virta}}</ref>

==Applications==

===Peak load leveling===
V2G vehicles can provide power to help balance grid loads by "valley filling"<ref>{{cite conference |first1=S.G. |last1=Liasi |first2=M.A. |last2=Golkar |title=Electric vehicles connection to microgrid effects on peak demand with and without demand response |year=2017 |conference=Iranian Conference on Electrical Engineering (ICEE) |location=Tehran |pages=1272–1277 |doi=10.1109/IranianCEE.2017.7985237}}</ref> (charging at night when demand is low) and "[[peak shaving]]" (sending power to the grid when demand is high; see [[duck curve]]).<ref name="Uddin 342–347">{{Cite journal|last1=Uddin|first1=Kotub|last2=Dubarry|first2=Matthieu|last3=Glick|first3=Mark B.|date=February 2018|title=The viability of vehicle-to-grid operations from a battery technology and policy perspective|journal=Energy Policy|volume=113|pages=342–347|doi=10.1016/j.enpol.2017.11.015|doi-access=free|bibcode=2018EnPol.113..342U }}</ref>  Peak load leveling supports [[regulation service]]s (keeping voltage and frequency stable) and provides [[spinning reserve]]s (to meet sudden demands for power). Coupling these services with "smart meters" enables V2G.<ref name="Pillai">{{Cite book|last1=Pillai|first1=Jayakrishnan R.|last2=Bak-Jensen|first2=Birgitte|title=2010 IEEE Vehicle Power and Propulsion Conference |chapter=Impacts of electric vehicle loads on power distribution systems |date=September 2010|pages=1–6|doi=10.1109/vppc.2010.5729191|isbn=978-1-4244-8220-7|s2cid=34017339}}</ref> V2G could buffer variable [[wind power|power]] sources by storing excess energy and providing it to the grid during high-load periods.

It has been proposed that [[public utilities]] would not have to build as many [[coal-fired power station|coal-fired]] and [[gas-fired power plant]]s to meet [[peak demand]] or as an insurance policy against [[power outage]]s.<ref name="woody">{{cite news |last=Woody |first=Todd |url=http://blogs.business2.com/greenwombat/2007/06/photo_green_wom.html |title=PG&E's Battery Power Plans Could Jump Start Electric Car Market |work=Green Wombat |date=2007-06-12 |access-date=2007-08-19 |archive-url=https://web.archive.org/web/20070814040717/http://blogs.business2.com/greenwombat/2007/06/photo_green_wom.html |archive-date=2007-08-14}}</ref> Local demand is easily measured, so [[Dynamic demand (electric power)|dynamic load leveling]] can be provided as needed on a highly local basis.<ref>{{cite patent |country=US |number=4317049 |inventor=SCHWEPPE, FRED C. |pubdate=1982-02-23 |title=Frequency adaptive, power-energy re-scheduler }}</ref>

Carbitrage, a [[portmanteau]] of 'car' and '[[arbitrage]]', is sometimes used to refer to the process of buying and selling power stored in a vehicle.<ref name="Smart_Garage">{{cite web |url=http://projectgetready.com/docs/SmartGarageCharretteReport_2.10.pdf |title=RMI Smart Garage Charrette Report |publisher=Rocky Mountain Institute |url-status=dead |archive-url=https://web.archive.org/web/20101007230703/http://projectgetready.com/docs/SmartGarageCharretteReport_2.10.pdf |archive-date=2010-10-07 }}</ref>

===Backup power===
Electric vehicles can generally store more than an average home's daily energy demand, and supply emergency power to a home for several days, using vehicle-to-home (V2H) transmission.

Though the concept of V2H charging is simple, putting it into action requires a technologically complex system. Charging stations must integrate software that communicates with the central grid to monitor real-time system demand.<ref name="vehicle-to-gird">{{cite web |last1=patel |first1=nirav |title=vehicle-to-grid |url=https://ev.nxccontrols.in/ |website=ev.nxccontrols.in |publisher=admin |access-date=2022-02-22 |ref=nxccontrols}}</ref><ref name="V2G" />

== Types==
California's grid operator, [[California Independent System Operator|CAISO]], defines four levels of Vehicle-Grid Interface (VGI):<ref>{{Cite web|url=http://www.caiso.com/documents/vehicle-gridintegrationroadmap.pdf|title=Vehicle-Grid Integration (VGI) Roadmap: Enabling vehicle-based grid services|date=February 2014|website=California ISO}}</ref>

# Unidirectional power flow (V1G) 
# V1G with aggregated resources
# V1G with fragmented actor objectives
# Bidirectional power flow (V2G)

=== V1G/Unidirectional V2G ===
V1G involves varying the time and rate at which an electric vehicle is charged. It is also known as unidirectional managed charging services, unidirectional V2G or "smart charging". V1G approaches include charging in the middle of the day to absorb solar power that would otherwise be discarded (load shedding) and varying the charge rate to provide [[Frequency response (electrical grid)|frequency response]] or load balancing services.{{cn|date=April 2024}}

=== Bidirectional local V2G (V2H, V2L, V2B, V2X) ===
Vehicle-to-home (V2H), vehicle-to-load (V2L), vehicle-to-vehicle (V2V),<ref name=electrek20231130/> and vehicle-to-building (V2B)—sometimes collectively termed vehicle-to-everything (V2X)—use the vehicle to provide power during a power outage or to displace grid energy with energy from possibly other energy sources stored in the vehicle's battery.<ref>{{cite web |url=https://www.emobilitysimplified.com/2019/12/what-is-vehicle-to-grid-v1g-v2g-v2x-v2h.html |title=What are V1G, V2G and V2H / V2B / V2X smart charging? {{!}} Integrating electric vehicles into power grid |first=Pon |last=Paulraj |website=E-Mobility Simplified |date=2019-12-10 |access-date=2020-02-22}}</ref>  The source energy may be renewable; for example, vehicles charged using solar power at work during the day could power a home through the night, without pulling power from the grid.

By 2022, V2X had not yet reached market deployment, except in Japan where commercial V2H solutions have been available since 2012.<ref name="Open Energi 2019">{{cite web |last=Cedillos |first=Dagoberto |date=2019-01-29 |title=V2X: how 'storage on wheels' can reshape our energy system |url=https://www.openenergi.com/v2x-how-storage-on-wheels-can-reshape-our-energy-system/ |access-date=2020-06-15 |website=Open Energi |archive-date=2021-05-15  |archive-url=https://web.archive.org/web/20210515104411/https://openenergi.com/v2x-how-storage-on-wheels-can-reshape-our-energy-system |url-status=dead }}</ref><ref>{{Cite journal |last1=Storck |first1=Carlos Renato |last2=Duarte-Figueiredo |first2=Fátima |date=29 January 2019 |title=A 5G V2X Ecosystem Providing Internet of Vehicles - MDPI |url=https://www.mdpi.com/1424-8220/19/3/550/pdf |journal=Sensors|volume=19 |issue=3 |page=550 |doi=10.3390/s19030550 |pmid=30699926 |pmc=6386933 |doi-access=free }}</ref> In 2022, [[Utrecht]] was installing thousands of bidirectional chargers in anticipation of the arrival of vehicles that support bidirectional energy flows.<ref>{{Cite web |last=Dumiak |first=Michael |date=2022-06-27 |title=This Dutch City Is Road-Testing Vehicle-to-Grid Tech |url=https://spectrum.ieee.org/vehicle-to-grid |access-date=2022-12-13 |website=IEEE Spectrum |language=en}}</ref>

By 2023, several vehicles supporting V2X energy transfer had come onto the market. The [[Ford F-150 Lightning]] supports 9.6&nbsp;kW of V2L or V2H power.<ref name=insideevs20210521>{{cite news |title=Ford F-150 Lightning Power Export Outlets And Home Backup Power |url=https://insideevs.com/news/508802/ford-f150-lightning-outlets-backup/ |last=Kane|first=Mark |date=21 May 2021 |work=[[InsideEVs]] |access-date=1 December 2023 }}</ref> [[Tesla, Inc.|Tesla]] began deliveries of a new light truck [[Cybertruck]] offering 11.5&nbsp;kW of V2H or V2L capability. <ref name=electrek20231130>{{cite news |title=Tesla releases Powershare bidirectional charging – on Cybertruck only, so far |url=https://electrek.co/2023/11/30/tesla-releases-powershare-bidirectional-charging-on-cybertruck-only-so-far/ |work=ElecTrek |date=30 November 2023 |access-date=1 December 2023 }}</ref>

=== Bidirectional V2G ===
V2G allows vehicles to supply electricity to the grid, with energy paid for by the operator of the utility or transmission system.<ref>{{cite conference |first1=S.G. |last1=Liasi |first2=S.M.T. |last2=Bathaee |title=Optimizing microgrid using demand response and electric vehicles connection to microgrid |conference=Smart Grid Conference (SGC) |location=Tehran |year=2017 |pages=1–7 |doi=10.1109/SGC.2017.8308873}}</ref> In many jurisdictions meeting power demands during periods of peak demand is much more expensive than at other times. Power from EVs is potentially a cheaper alternative. In addition, EV power can facilitate ancillary services<ref>{{Cite journal|url=https://www.mdpi.com/1996-1073/12/12/2443/pdf|title=Electric vehicle into the grid: Charging methodologies aimed at providing ancillary services considering battery degradation |date=25 June 2019 |journal=Energies |volume=12 |issue=12 |page=2443 |doi=10.3390/en12122443 |doi-access=free |last1=Saldaña |first1=Gaizka |last2=San Martin |first2=Jose Ignacio |last3=Zamora |first3=Inmaculada |last4=Asensio |first4=Francisco Javier |last5=Oñederra |first5=Oier |hdl=10810/41346 |hdl-access=free }}</ref> such as load-balancing and frequency control, including primary frequency regulation and secondary reserve.<ref>{{cite web |last1=Schmidt |first1=Bridie |title="First" vehicle-to-grid electric car charger goes on sale in Australia |url=https://thedriven.io/2020/10/27/first-vehicle-to-grid-electric-car-charger-goes-on-sale-in-australia/ |website=The Driven |location=Australia |date=27 October 2020}}</ref>

V2G requires specialized hardware (such as bidirectional [[inverters]]), has significant energy losses and limited round-trip efficiency, and the charge/discharge cycling may shorten battery life. A 2016 V2G project in California was done as a pilot by [[Southern California Edison]] and found that revenues from the project were lower than project administration costs, eliminating its economic benefits.<ref>{{Cite web |date=2017 |title=Southern California Edison Company's Department of Defense Vehicle-to-Grid Final Report |url=http://www.cpuc.ca.gov/WorkArea/DownloadAsset.aspx?id=6442455793 |website=California Public Utilities Commission |access-date=2019-05-10  |archive-date=2021-02-27  |archive-url=https://web.archive.org/web/20210227223431/https://www.cpuc.ca.gov/WorkArea/DownloadAsset.aspx?id=6442455793 |url-status=dead }}</ref><!-- this says a lot about this particular project, by SCE, in 2016.  It says little about other projects, with other technologies, implemented by parties who might have more incentives to make it economically sound. -->

=== Bidirectional DC-charging ===
EVs typically allow fast [[Charging station#AC to DC conversion|DC-charging]], with the transformer in a charging station connected directly to the vehicle battery. Technology is being developed for bidirectional DC-charging to and from the station, without needing extra hardware in the car, having the DC-to-AC converter in the station. In principle, EVs without hardware support for V2G could gain bidirectionality capability with only a software upgrade.<ref name=tdio20230123>{{cite news |url=https://thedriven.io/2023/01/23/world-first-trial-with-ccs-could-open-up-vehicle-to-everything-technology-to-all-evs/ |title=World first" trial with CCS could open up vehicle-to-everything technology to all EVs |first=Daniel |last=Bleakley |work=The Driven |location=Australia |date=2023-01-23 |access-date=2024-03-30}}</ref><ref>{{cite news |url=https://www.ambibox.de/en/products/ambicharge |title=Bidirectional DC charging technology |publisher=ambicharge |location=Germany |access-date=2024-03-30}}</ref>

== Efficiency ==
Most modern EVs use lithium-ion cells that offer round-trip efficiency greater than 90%.<ref>{{cite conference |last1=Valøen |first1=Lars Ole |last2=Shoesmith |first2=Mark I. |year=2007 |title=The effect of PHEV and HEV duty cycles on battery and battery pack performance |conference=2007 Plug-in Highway Electric Vehicle Conference }}</ref> Efficiency depends on factors like charge rate, charge state, battery [[state of health]], and temperature.<ref>{{cite web|url= https://www.researchgate.net/publication/261873996 |title=Energy Regeneration and Efficiency in an Electro-Hydraulic Forklift with Lithium-Titanate Batteries, Chapter 5 Analysis. (PDF Download Available)|work=ResearchGate |author=Tatiana Minav |date=2014-03-26 |access-date=2017-05-20 |quote=battery efficiency during performed testes in average is 98 %}}</ref><ref>{{cite web |url=http://dolgin.net/Charging%20Lithium-Ion%20Batteries.html |title=Charging Lithium-ion Batteries |work=Battery University |publisher=Cadex |date=2016-01-29 |access-date=2018-05-13 |quote=Charge efficiency is 97 to 99 percent}}</ref>
 
Most energy losses are from system components other than the battery, particularly power electronics such as inverters.<ref name=energy2017>{{Cite journal|date=2017-05-15|title=Measurement of power loss during electric vehicle charging and discharging|journal=Energy|volume=127|pages=730–742|doi=10.1016/j.energy.2017.03.015|issn=0360-5442|last1=Apostolaki-Iosifidou|first1=Elpiniki|last2=Codani|first2=Paul|last3=Kempton|first3=Willett|doi-access=free|bibcode=2017Ene...127..730A }}</ref> One study found round-trip efficiency for V2G systems in the range of 53% to 62%.<ref>{{Cite journal|date=2018-01-01|title=Comments on "Measurement of power loss during electric vehicle charging and discharging" – Notable findings for V2G economics|journal=Energy|volume=142|pages=1139–1141|doi=10.1016/j.energy.2017.10.081|issn=0360-5442|last1=Shirazi|first1=Yosef A.|last2=Sachs|first2=David L.|bibcode=2018Ene...142.1139S }}</ref> Another study reported efficiency of about 70%.<ref>{{Cite journal|date=2018-01-01|title=Reply to Shirazi and Sachs comments on "Measurement of Power Loss During Electric Vehicle Charging and Discharging"|journal=Energy|volume=142|pages=1142–1143|doi=10.1016/j.energy.2017.10.080|issn=0360-5442|last1=Apostolaki-Iosifidou|first1=Elpiniki|last2=Kempton|first2=Willett|last3=Codani|first3=Paul|bibcode=2018Ene...142.1142A }}</ref> Overall efficiency depends on many factors and can vary widely.<ref name=energy2017 /><ref name="ev.nxccontrols">{{cite web |last1=patel |first1=nirav |title=Vehicle-to-grid |url=https://ev.nxccontrols.in/blog/vehicle-to-grid-technology-work/ |website=NxControls |date=30 March 2024 |location=India |access-date=2024-03-30}}</ref>

==Implementation by country==
According to a study by the U.S. Department of Energy (DOE), the increasing use of plug-in electric vehicles and other electricity-dependent technologies could increase the strain on US power grids by as much as 38% by 2050. Coping with this heightened demand presents a significant challenge for both power companies and government agencies.<ref name="vehicle-to-grid">{{cite web |last1=patel |first1=nirav |title=v2g |url=https://ev.nxccontrols.in/ |website=ev.nxccontrols.in |publisher=admin |access-date=2022-02-22 |ref=ev.nxccontrols}}</ref><ref name="V2G" />

===United States===
In July 2022, eight electric school buses in the [[San Diego Gas & Electric]] (SDG&E) service territory were part of a five-year pilot V2G project to boost reliability during electricity failures.<ref>{{cite web |last1=Nora |first1=Manthey |title=Nuvve and SDG&E launch V2G scheme for electric school buses |url=https://www.electrive.com/2022/07/20/nuvve-and-sdge-launch-v2g-scheme-for-electric-school-buses/ |website=Electrive |date=20 July 2022 |access-date=July 20, 2022}}</ref><ref>{{cite news |last1=Hudson |first1=Sangree |title=California Sees First V2G Reliability Project |url=https://www.rtoinsider.com/articles/30560-california-sees-first-v2g-reliability-project |access-date=August 2, 2022 |agency=RTO Insider |date=August 2, 2022}}</ref> Using V2G software from Nuvve,<ref>{{Cite web |title=Home |url=https://nuvve.com/ |access-date=2022-08-15 |website=NUVVE Holding Corp |language=en-US}}</ref> the bus batteries are aggregated with others in a nearby school district to form a participating resource under the Emergency Load Reduction Program ([[ELRP]]),<ref>{{Cite web |title=Emergency Load Reduction Program |url=https://www.cpuc.ca.gov/industries-and-topics/electrical-energy/electric-costs/demand-response-dr/emergency-load-reduction-program |access-date=2022-08-15 |website=[[California Public Utilities Commission]]}}</ref> which was initiated in 2021 by the [[California Public Utilities Commission]]. SDG&E, [[Pacific Gas and Electric Company|Pacific Gas and Electric]] and [[Southern California Edison]] to manage the pilot.

In September 2022, the BIDIRECTIONAL Act was introduced in the US Senate, to "create a program dedicated to deploying electric school buses with bidirectional vehicle-to-grid (V2G) flow capability”.<ref>{{Cite web |last=Johnson |first=Peter |date=2022-09-30 |title=BIDIRECTIONAL Act introduced in US Senate to promote electric school buses feeding grid |url=https://electrek.co/2022/09/30/bidirectional-act-promotes-electric-school-buses-with-v2g/ |access-date=2022-10-02 |website=Electrek |language=en-US}}</ref>

In North America, at least two major school-bus manufacturers—[[Blue Bird Corporation|Blue Bird]] and Lion—are working on proving the benefits of electrification and V2G technology. As of 2020, school buses in the U.S. used $3.2B of diesel a year. Their electrification could help to stabilize the electricity grid, lessen the need for power plants, and reduce gas and particulate pollution and carbon dioxide from exhaust emissions.<ref>{{Cite web|url=https://motherboard.vice.com/en_us/article/bj3x74/electric-school-buses-vehicle-to-grid-v2g-power-grid|title=Electric School Buses Can Be Backup Batteries For the US Power Grid|last1=Lindeman|first1=Tracey|last2=Pearson|first2=Jordan|date=2018-05-15|website=Motherboard|access-date=2018-12-13|last3=Maiberg|first3=Emanuel}}</ref><ref>{{Cite news|last=Engle|first=John|date=2021-12-02|title=Electric school bus charging hub could provide 'blueprint' for grid support|language=en-US|work=Renewable Energy World|url=https://www.renewableenergyworld.com/storage/electric-school-bus-charging-hub-could-provide-blueprint-for-grid-support/|access-date=2022-02-06}}</ref><ref>{{Cite web|last=Muller|first=Joann|date=2020-01-10|title=Fleets of electric school buses are being tested to store power for the grid|url=https://www.axios.com/electric-school-buses-vehicle-to-grid-power-19f7b6b1-662b-4501-a96e-dcf3fd57a886.html|access-date=2022-02-06|website=Axios|language=en}}</ref>

In 2017, at the [[University of California San Diego]], V2G technology provider Nuvve launched a pilot program called INVENT, funded by the [[California Energy Commission]], with the installation of 50 V2G bidirectional charging stations around the campus.<ref name="xconomy.com">{{Cite web|url=https://xconomy.com/san-diego/2017/06/16/startup-pioneers-ev-to-grid-technology-in-pilot-at-uc-san-diego/|title=Xconomy: Startup Pioneers EV-to-Grid Technology in Pilot at UC San Diego|date=2017-06-16|website=Xconomy|access-date=2018-12-13}}</ref> The program expanded in 2018 to include a fleet of PEVs for its Triton Rides shuttle service.<ref>{{Cite web|url=https://nuvve.com/2018/10/30/ucsd-triton-rides/|title=UC SAN DIEGO EXPANDS TRITON RIDES PROGRAM WITH VEHICLE-TO-GRID SERVICE FROM NUVVE|date=2018-10-30|website=NUVVE Corp|access-date=2018-12-13|archive-date=2019-08-21 |archive-url=https://web.archive.org/web/20190821143441/https://nuvve.com/2018/10/30/ucsd-triton-rides/|url-status=dead}}</ref>

In 2018 [[Nissan]] launched a pilot program under the Nissan Energy Share initiative in partnership with V2G systems company Fermata Energy to use V2G technology to partially power Nissan North America's headquarters in [[Franklin, Tennessee]].<ref>{{Cite web | url=https://usa.nissannews.com/en-US/releases/release-cd8a64d603d241f7b319fc6c1c33397f-nissan-leaf-helps-to-power-company-s-north-american-facilities-with-new-charging-technology | title=Nissan LEAF helps to power company's North American facilities with new charging technology| date=28 November 2018}}</ref> In 2020 Fermata Energy's bidirectional electric vehicle charging system became the first to be certified to the North American safety standard, [[UL (safety organization)|UL]] 9741, the Standard for Bidirectional Electric Vehicle (EV) Charging System Equipment.<ref>{{Cite web | url=https://www.ul.com/news/fermata-energy-receives-first-ul-certification-%27vehicle-grid%27-electric-vehicle-charging-system |title = Fermata Energy Receives the First UL Certification for 'Vehicle-to-Grid' Electric Vehicle Charging System}}</ref>

===Japan===
Japan planned to spend $71.1 billion to upgrade existing grid infrastructure.{{citation needed|date=April 2024}} Average Japanese homes use 10 to 12 kWh/day. The [[Nissan Leaf]]'s 24 kWh battery capacity, could provide up to two days of power.{{citation needed|date=September 2018}}

In November 2018 in Toyota City, Aichi Prefecture, Toyota Tsusho Corporation and Chubu Electric Power Co., Inc initiated V2G demonstrations with electric vehicles. The demonstration examined how V2G systems balance demand and supply and power grid impacts. Two bidirectional charging stations, connected to a V2G aggregation server managed by Nuvve Corporation, were installed at a parking lot in [[Aichi Prefecture]].<ref>{{Cite web|url=https://www.marketscreener.com/TOYOTA-TSUSHO-CORP-6494673/news/Toyota-Tsusho-and-Chubu-Electric-Power-Announce-to-Initiate-Japan-s-First-Ever-Demonstration-Proje-27561256/|title=Toyota Tsusho : and Chubu Electric Power Announce to Initiate Japan's First Ever Demonstration Project of Charging and Discharging from Storage Batteries of Electric Vehicles to the Electric Grid |last=MarketScreener|website=MarketScreener|date=7 November 2018 |access-date=2019-01-09}}</ref>

===Denmark===
The Edison Project intends to install enough turbines to accommodate 50% of Denmark's total power needs, while using V2G to protect the grid. The Edison Project plans to use PEVs while they are plugged into the grid to store additional wind energy that the grid cannot handle. During the hours of peak energy use, or when the wind is calm, the power stored in these PEVs will be fed into the grid. To aid in the acceptance of PEVs, zero emission vehicles received government subsidies.{{Citation needed|date=August 2022}}

Following the Edison project, the Nikola project was started<ref>{{cite web |url=http://www.nikola.droppages.com/ |title=Home |publisher=Nikola |access-date=2016-07-12}}</ref> which focused on demonstrating V2G technology in a laboratory setting at the Risø Campus of the [[Technical University of Denmark]] (DTU). DTU is a partner along with Nuvve and Nissan. The Nikola project was completed in 2016, laying the groundwork for the Parker project, which used a fleet of EVs to demonstrate the technology in a real-life setting. This project was partnered by [[Technical University of Denmark|DTU]],<ref name=integration>{{cite web |url=http://orbit.dtu.dk/files/101856208/ISGT2014IstanbulNikola_Final.pdf |title=The Nikola project intelligent electric vehicle integration |last1=Andersen |first1=Peter Bach |last2=Marinelli |first2=Mattia |last3=Olesen |first3=Ole Jan |last4=Andersen |first4=Claus Amtrup |last5=Poilasne |first5=Gregory |last6=Christensen |first6=Bjoern |last7=Alm |first7=Ole |publisher=Technical University of Denmark |year=2014 |access-date=2016-07-12}}</ref> Insero, Nuvve, [[Nissan]] and [[Frederiksberg Forsyning]] (a Danish distribution system operator in Copenhagen). The partners explored commercial opportunities by systematically testing and demonstrating V2G services across car brands. Economic and regulatory barriers were identified as well as the economic and technical impacts of the applications on the power system and markets.<ref>{{Cite web|url=https://parker-project.com/danish-project-defines-the-electric-vehicle-of-the-future/|title=Parker {{!}} Danish project defines the electric vehicle of the future|access-date=2019-01-09}}</ref> The project started in August 2016 and ended in September 2018.

===United Kingdom===
Starting in January 2011, programs and strategies to assist in PEV adoption were implemented.

In 2018, [[EDF Energy]] announced a partnership with Nuvve, to install up to 1,500 V2G chargers. The chargers were to be offered to EDF Energy's business customers and at its own sites to provide up to 15 MW of energy storage capacity.<ref>{{Cite web|url=https://www.oilandgas360.com/edf-energy-and-nuvve-corporation-announce-plans-to-install-1500-smart-electric-chargers-in-the-united-kingdom/|title=EDF Energy and Nuvve Corporation Announce Plans to Install 1,500 Smart Electric Chargers in the United Kingdom|date=2018-10-31|website=Oil & Gas 360|access-date=2019-01-09}}</ref>

In October 2019, a consortium called Vehicle to Grid Britain (V2GB) released a research report on the potential of V2G technologies.<ref>{{Cite web|url=https://es.catapult.org.uk/case-studies/vehicle-to-grid-britain/|title=Vehicle-to-Grid Britain|date=2019-10-01|website=Energy Systems Catapult|language=en-GB|access-date=2020-01-09|ref=Vehicle-to-Grid Britain/V2GB Oct. 2019}}</ref><ref>{{Cite web|url=https://www.greentechmedia.com/articles/read/why-is-vehicle-to-grid-taking-so-long-to-happen|title=Why Is Vehicle-to-Grid Taking So Long to Happen?|last=Deign|first=Jason|date=2018-03-19|website=Greentech Media|access-date=2020-01-09|ref=GTM Mar. 2018: Why is V2G taking so long?}}</ref>

===Poland===
[[Solaris Bus & Coach|Solaris]] opened a Charging Park in [[Bolechowo, Greater Poland Voivodeship|Bolechowo, Poland]] on September 29, 2022 intended to test charging and discharging of EVs.<ref>{{Cite web |date=2022-10-04 |title=Solaris opens new warehouse hall and charging park for e-vehicles in Bolechowo |url=https://www.sustainable-bus.com/news/solaris-new-warehouse-charging-park-bolechowo/ |access-date=2022-10-05 |website=Sustainable Bus |language=en-US}}</ref>

===Australia ===

Since 2020, the [[Australian National University]]'s (ANU) Realising Electric Vehicle-to-grid Services (REVS) team has been studying the reliability and viability of V2G at scale,<ref>{{cite web |title=Electric vehicle fleets set to be on-call to backup the grid |url=https://www.anu.edu.au/news/all-news/electric-vehicle-fleets-set-to-be-on-call-to-backup-the-grid |publisher=Australian National University |location=Canberra |date=8 July 2020 |access-date=30 November 2022}}</ref> spinning off the Battery Storage and Grid Integration Project<ref>{{cite web |url=https://bsgip.com |title=Battery Storage and Grid Integration Project |location=Canberra |access-date=30 November 2022}}</ref> initiative.

In 2022 the first V2G charger became available to purchase in Australia, but delays in rolling them out occurred due to regulatory processes, each State Power Authority needing to certify them as compliant (following Australian government approval). There has also been limited uptake due to high prices and very few EVs being approved to use V2G (at 2023, only the Nissan Leaf EV and some Mitsubishi hybrid EVs). This roll-out follows ANU researchers' production of a comprehensive review of international V2G projects.<ref>{{cite web |url=https://arena.gov.au/knowledge-bank/the-a-z-of-v2g/ |title=A to Z of V2G – A comprehensive analysis of vehicle-to-grid technology worldwide |publisher=Australian Renewable Energy Agency |first1=Laura |last1=Jones |first2=Kathryn |last2=Lucas-Healey |first3=Björn |last3=Sturmberg |first4=Hugo |last4=Temby |first5=Monirul |last5=Islam |date=January 2021 |access-date=3 January 2023}}</ref>{{Page needed|date=January 2023}}

===Germany===
A project in Germany by The Mobility House in partnership with Nissan and TenneT used the Nissan Leaf to store energy,<ref>{{cite web |url=https://www.v2g-hub.com/projects/v2g-redispatch-tennet-nissan-the-mobility-house-nissan/ |title=V2G Redispatch - TenneT, Nissan, The Mobility House |publisher=V2GHub |date=2023 |access-date=3 October 2023}}</ref> the main idea being to generate an essential solution for the German energy market: wind energy from the north of the country is used to charge the EVs while EVs supply the grid during demand peaks, reducing the use of fossil fuels. The project used ten vehicle charging stations. Smart energy redistribution measures were controlled by software. The results showed that electromobility can be used to flexibly control renewable generation sources that vary with the climate.

==Research==

=== Edison ===
[[Denmark]]'s Edison project, an abbreviation for 'Electric vehicles in a Distributed and Integrated market using Sustainable energy and Open Networks', was a partially state funded research project on the island of [[Bornholm]] in Eastern Denmark. The consortium included [[IBM]], [[Siemens]], the hardware and software developer EURISCO, Denmark's largest energy company [[Ørsted (company)|Ørsted]] (formerly DONG Energy), the regional energy company Østkraft, the [[Technical University of Denmark]] and the Danish Energy Association. It explored how to balance the unpredictable electricity loads generated by Denmark's wind farms, then generating approximately 20 percent of the country's electricity, by using PEVs and their accumulators. The aim of the project was to develop necessary infrastructure.<ref>{{cite web |title=Intelligent power grid |date=9 February 2021 |url=http://www.zurich.ibm.com/edison/ |publisher=IBM Research |location=Zurich }}</ref> At least one rebuilt V2G-capable [[Scion xB|Toyota Scion]] will be used in the project.<ref>{{cite web |title=WP3 - Distributed integration technology development |url=http://www.edison-net.dk/~/media/EDISON/Reports/EDISON_WP3_-_Distributed_integration_technology_development.ashx |publisher=Edison |access-date=2011-08-30 |archive-url=https://web.archive.org/web/20110829092503/http://www.edison-net.dk/~/media/EDISON/Reports/EDISON_WP3_-_Distributed_integration_technology_development.ashx |archive-date=2011-08-29 |url-status=dead }}</ref> The project was important in Denmark's efforts to expand its wind-power generation to 50% by 2020.<ref>{{cite web |title = Danish Climate and Energy Policy |url = http://www.ens.dk/en/policy/danish-climate-energy-policy |publisher = Danish Energy Agency |year = 2013 |access-date = 2016-03-08 |url-status = dead |archive-url = https://web.archive.org/web/20160309050145/http://www.ens.dk/en/policy/danish-climate-energy-policy |archive-date = 2016-03-09 }}</ref> According to a source of the UK newspaper ''[[The Guardian]]'', 'It's never been tried at this scale' previously.<ref>{{cite news |last=Graham-Rowe |first=Duncan |title=Denmark to power electric cars by wind in vehicle-to-grid experiment |url=https://www.theguardian.com/environment/2009/jun/19/denmark-wind-electric-cars |newspaper=The Guardian |location=London |date=2009-06-19 |access-date=2011-08-30}}</ref> The project concluded in 2013.<ref>{{cite web |url=http://www.edison-net.dk/EDISON%20closed.aspx |title=The Edison project is successfully closed!!! |website=Edison |first=Jan |last=Rasmussen |date=2013-07-11 |access-date=2016-03-08 |archive-url=https://web.archive.org/web/20160405223154/http://www.edison-net.dk/EDISON%20closed.aspx |archive-date=2016-04-05 |url-status=dead }}</ref>

=== E.ON and gridX ===
In 2020, the utility company [[E.ON]] developed a V2H solution with gridX.<ref>{{Cite web|title=Press Release: gridX and E.ON develop optimised charging and Vehicle2Home solution|url=https://www.gridx.ai/press-releases/gridx-and-e-on-develop-optimised-charging-and-vehicle2home-solution|access-date=2021-01-18|website=gridX}}</ref> The two companies implemented their solution in a private household to test the interaction of a [[Photovoltaics|photovoltaic]] (PV) system, battery storage and bidirectional charging. The house is equipped with three batteries with a combined capacity of 27 kWh, a DC charger and a PV system of 5.6 kWp ([[kilowatt-peak]]). A 40 kWh Nissan Leaf was used.

===Southwest Research Institute===
In 2014, [[Southwest Research Institute]] (SwRI) developed the first V2G aggregation system qualified by the [[Electric Reliability Council of Texas]] (ERCOT). The system allows owners of electric delivery truck fleets to participate. When the grid frequency drops below 60 Hertz, the system suspends vehicle charging, removing that load on the grid, allowing the frequency to rise towards normal. The system operates autonomously.<ref>{{cite web |title=SwRI develops first ERCOT-qualified vehicle-to-grid aggregation system |url=http://www.swri.org/9what/releases/2014/vehicle-to-grid.htm#.VO66HfldWLY |website=Southwest Research Institute |access-date=2015-02-26|date=2014-01-14 }}</ref>

The system was originally developed as part of the Smart Power Infrastructure Demonstration for Energy Reliability and Security (SPIDERS) Phase II program, led by Burns and McDonnell Engineering Company, Inc.<ref>{{cite web|title=SPIDERS: The Smart Power Infrastructure Demonstration for Energy Reliability and Security|url=http://energy.sandia.gov/wp/wp-content/gallery/uploads/SPIDERS_Fact_Sheet_2012-1431P.pdf|publisher=Sandia National Laboratories|access-date=2015-02-26 |archive-date=2013-02-16 |archive-url=https://web.archive.org/web/20130216191807/http://energy.sandia.gov/wp/wp-content/gallery/uploads/SPIDERS_Fact_Sheet_2012-1431P.pdf|url-status=dead}}</ref> In November 2012, SwRI was awarded a $7 million contract from the [[United States Army Corps of Engineers|U.S. Army Corps of Engineers]] to demonstrate V2G.<ref>{{cite web |title=SwRI will participate in a U.S. Army program to demonstrate alternative sources for an emergency electrical power grid |url=http://www.swri.org/9what/releases/2012/army-spiders.htm |website=Southwest Research Institute |access-date=2015-02-26|date=2012-11-13 }}</ref> In 2013, SwRI researchers tested five DC fast-charge stations. The system passed integration and acceptance testing in August 2013.<ref>{{cite web |title=SwRI deploys novel vehicle-to-grid aggregation system |url=http://www.swri.org/9what/releases/2013/vehicle-aggregation.htm#.VO66HvldWLY |website=Southwest Research Institute |access-date=2015-02-26|date=2013-09-09 }}</ref>

=== Delft University of Technology===
Prof. Dr. Ad van Wijk, Vincent Oldenbroek and Dr. Carla Robledo, researchers at [[Delft University of Technology]], in 2016 conducted research on V2G technology with hydrogen [[FCEV]]s. Both experimental work with V2G FCEVs and techno-economic scenario studies for 100% renewable integrated energy and transport systems were done, using hydrogen and electricity as energy carriers.<ref>{{Cite journal|last1=Oldenbroek|first1=Vincent|last2=Verhoef|first2=Leendert A.|last3=van Wijk|first3=Ad J. M.|date=2017-03-23|title=Fuel cell electric vehicle as a power plant: Fully renewable integrated transport and energy system design and analysis for smart city areas|journal=International Journal of Hydrogen Energy|volume=42|issue=12|pages=8166–8196|doi=10.1016/j.ijhydene.2017.01.155|bibcode=2017IJHE...42.8166O |url=https://repository.tudelft.nl/islandora/object/uuid%3Aa825f9c1-725b-4dc3-8745-25399b424c9d/datastream/OBJ/download}}</ref> A [[Hyundai ix35 FCEV]] was modified to deliver up to 10&nbsp;kW DC power<ref name="AppliedEnergy" /> while maintaining road readiness. With Accenda they developed a V2G unit converting the vehicle's DC power into 3-phase AC power and injecting it into the grid.<ref name="AppliedEnergy" /> The Future Energy Systems Group tested whether FCEVs could offer frequency reserves.<ref>{{Cite journal|last=Michelle|first=Poorte|date=2017|title=Technical and economic feasibility assessment of a Car Park as Power Plant offering frequency reserves|url=https://repository.tudelft.nl/islandora/object/uuid:814c3699-8cf6-41b6-8633-c772dcc814e9?collection=education}}</ref>

===University of Delaware===
Kempton, Advani, and Prasad conducted V2G research. Kempton published articles on the technology and the concept.<ref name="V2G">{{cite web |date=June 2001 |title=V2G : Vehicle to Grid Power |url=http://www.udel.edu/V2G |access-date=2008-02-05}}</ref><ref>{{cite web |url=http://www.udel.edu/V2G/resources/test-v2g-in-pjm-jan09.pdf |title=A Test of Vehicle-to-Grid (V2G) for Energy Storage and Frequency Regulation in the PJM System |first1=Willett |last1=Kempton |first2=Victor |last2=Udo |first3=Ken |last3=Huber |first4=Kevin |last4=Komara |first5=Steve |last5=Letendre |first6=Scott |last6=Baker |first7=Doug |last7=Brunner |first8=Nat |last8=Pearre |publisher=University of Delaware |date=November 2008 |access-date=2016-03-08}}</ref>

An operational implementation in Europe was conducted through the German government-funded MeRegioMobil project with Opel as vehicle partner and utility EnBW providing grid expertise.<ref name="meregio">{{cite journal |last1=Brinkman |first1=Norm |last2=Eberle |first2=Ulrich |last3=Formanski |first3=Volker |last4=Grebe |first4=Uwe-Dieter |last5=Matthe |first5=Roland |year=2012 |title=Vehicle Electrification - Quo Vadis? |doi=10.13140/2.1.2638.8163}}</ref> Other investigators are the [[Pacific Gas and Electric Company]], [[Xcel Energy]], the [[National Renewable Energy Laboratory]], and, in the [[United Kingdom]], the [[University of Warwick]].<ref name="NTY">{{cite journal |last=Motavalli |first=Jim |date=2007-09-02 |title=Power to the People: Run Your House on a Prius |url=https://www.nytimes.com/2007/09/02/automobiles/02POWER.html |journal=[[New York Times]] |access-date=2014-12-20}}</ref>

In 2010, Kempton and Poilasne co-founded Nuvve, a V2G solutions company. The company formed industry partnerships and implemented V2G pilot projects on five continents.<ref name="xconomy.com" /><ref>{{cite web |url=https://nuvve.com/our-story/ |title=Our Story - NUVVE Corp |access-date=2020-02-22}}</ref>

===Lawrence Berkeley National Laboratory===
[[Lawrence Berkeley National Laboratory]] developed V2G-Sim, a simulation platform used to model spatial and temporal driving and charging behavior of individual PEVs on the grid. Its models investigate the challenges and opportunities of V2G services, such as modulation of charging time and charging rate for peak [[demand response]] and [[utility frequency]] regulation. Preliminary findings indicated that controlled V2G service can provide peak-shaving and valley-filling services to balance daily electric load and mitigate the duck curve. Uncontrolled vehicle charging was shown to exacerbate the duck curve.<ref>{{cite web |title=Used EV Batteries Get New Life Powering the Grid |url=https://www.fleetcarma.com/used-ev-batteries-power-grid/ |publisher=Fleetcarma.com |access-date=2017-10-06 }}</ref>

V2G-Sim reported that, assuming daily V2G service from 7pm to 9pm at a charging rate of 1.440&nbsp;kW over ten years, V2G would have minor battery degradation impacts on PEVs compared with cycling losses and calendar aging, incremental capacity losses being 2.68%, 2.66%, and 2.62% respectively.<ref>{{cite book |first1=Dai |last1=Wang |first2=Samveg |last2=Saxena |first3=Jonathan |last3=Coignard |first4=Elpiniki |last4=Iosifidou |first5=Xiaohong |last5=Guan |title=2016 IEEE Power and Energy Society General Meeting (PESGM) |chapter=Quantifying electric vehicle battery degradation from driving vs. V2G services |date=2016-07-21 |pages=1–5 |doi=10.1109/PESGM.2016.7741180 |isbn=978-1-5090-4168-8 |s2cid=434374 }}</ref>

===Nissan and Enel===
In May 2016, Nissan and [[Enel]] power company announced a collaborative V2G trial in the United Kingdom.<ref>
{{cite web
 |title=Nissan and Enel Launch Groundbreaking Vehicle-to-grid Project in the UK
 |url=http://newsroom.nissan-europe.com/uk/en-gb/media/pressreleases/145248
 |publisher=Nissan Newsroom UK
 |access-date=2016-11-19
 }}
</ref> The trial used 100 V2G charging units including Nissan Leaf and e-NV200 electric vans.

===University of Warwick===
[[WMG, University of Warwick]] and [[Jaguar Land Rover]] collaborated with the Energy and Electrical Systems group of the university. They analysed commercially available PEVs over a two-year period. Using a model of battery degradation, they discovered that, for typical driving patterns, some patterns of V2G storage were able to significantly increase battery longevity compared with conventional charging strategies.<ref>{{cite journal |url=http://wrap.warwick.ac.uk/88018/13/WRAP-possibility-extending-lifetime-lithium-ion-batteries-Marco-2017.pdf |title=On the possibility of extending the lifetime of lithium-ion batteries through optimal V2G facilitated by an integrated vehicle and smart-grid system |first1=Kotub |last1=Uddin |first2=Tim |last2=Jackson |first3=Widanalage D. |last3=Widanage |first4=Gael |last4=Chouchelamane |first5=Paul A. |last5=Jennings |first6=James |last6=Marco |journal=Energy |volume=133 |pages=710–722 |publisher=University of Warwick |date=2017-04-25 |access-date=2018-05-13|doi=10.1016/j.energy.2017.04.116 |bibcode=2017Ene...133..710U }}</ref>

==Drawbacks==
The more a battery is used the sooner it needs replacing. As of 2016, replacement cost was approximately one-third of the cost of the car.<ref>{{cite web |url=http://electricvehicles.caa.ca/frequently-asked-questions/#q7 |title=Frequently Asked Questions |publisher=Canadian Automobile Association |work=Electric Vehicles |access-date=2016-03-08}}</ref>  Batteries degrade with use.<ref>{{cite web |url=https://na.industrial.panasonic.com/sites/default/pidsa/files/uf103450pn_1.pdf |title=Lithium Ion UF103450P |publisher=Panasonic |year=2012 |access-date=2016-03-08 |archive-date=2016-03-08  |archive-url=https://web.archive.org/web/20160308131252/https://na.industrial.panasonic.com/sites/default/pidsa/files/uf103450pn_1.pdf |url-status=dead }}</ref> [[JB Straubel]], then chief technology officer of [[Tesla Inc.|Tesla Inc]], discounted V2G, claiming that battery wear outweighs economic benefit.<ref>{{cite news |url=http://cleantechnica.com/2016/08/22/vehicle-to-grid-used-ev-batteries-grid-storage/ |title=Why Vehicle-To-Grid & Used EV Battery Storage Isn't Logical |first=Zachary |last=Shahan |work=Clean Technica |date=2016-08-22 |access-date=2016-08-22}}</ref> A 2017 study found decreasing capacity,<ref>{{cite web|url= http://www.greencarcongress.com/2017/05/20170515-v2g.html |title=Green Car Congress: Hawaii study finds vehicle-to-grid discharge detrimental to EV batteries|work=GreenCarCongress |date= 2017-05-15 |access-date= 2017-05-18 }}</ref><ref>{{cite journal | last1 = Dubarry | first1 = Matthieu | last2 = Devie | first2 = Arnaud | last3 = McKenzie | first3 = Katherine | year = 2017 | title = Durability and reliability of electric vehicle batteries under electric utility grid operations: Bidirectional charging impact analysis | journal = Journal of Power Sources | volume = 358 | pages = 39–49 | doi = 10.1016/j.jpowsour.2017.05.015 | bibcode = 2017JPS...358...39D | doi-access = free }}</ref> and a 2012 hybrid-EV study found minor benefit.<ref>{{cite thesis |url=https://kilthub.cmu.edu/articles/Plug-in_hybrid_electric_vehicles_battery_degradation_grid_support_emissions_and_battery_size_tradeoffs/6721085 |title=Plug-in hybrid electric vehicles: battery degradation, grid support, emissions, and battery size tradeoffs |first=Scott B. |last=Peterson |publisher=Carnegie Mellon University |location=US |date=2012-01-05 |page=8}}</ref>

A 2015 study<ref>{{Cite journal|date=2015-12-01|title=A cost-benefit analysis of alternatively fueled buses with special considerations for V2G technology|journal=Energy Policy|volume=87|pages=591–603|doi=10.1016/j.enpol.2015.09.038|issn=0301-4215|last1=Shirazi|first1=Yosef|last2=Carr|first2=Edward|last3=Knapp|first3=Lauren|bibcode=2015EnPol..87..591S |s2cid=154598691 }}</ref> found that economic analyses favorable to V2G failed to include many&nbsp;of the less obvious costs associated with its implementation. When these less obvious costs were included, the study reported that V2G was an economically inefficient solution.

Another common criticism related to efficiency is that cycling power into and out of a battery, which includes "inverting" the DC power to AC, inevitably incurs energy losses. This cycle of [[Electrical efficiency|energy efficiency]] may be compared with the 70–80% efficiency of large-scale [[pumped-storage hydroelectricity]].<ref>{{cite web |last1=Levine |first1=John |title=Pumped Hydroelectric Energy Storage and Spatial Diversity of Wind Resources as Methods of Improving Utilization of Renewable Energy Sources |url=http://www.colorado.edu/engineering/energystorage/files/MSThesis_JGLevine_final.pdf |publisher=Colorado University |location=US |access-date=2014-08-28 |archive-url=https://web.archive.org/web/20140801113053/http://www.colorado.edu/engineering/energystorage/files/MSThesis_JGLevine_final.pdf |archive-date=2014-08-01 |url-status=dead }}</ref>

Power companies must be willing to adopt the technology in order to allow vehicles to give power to the power grid.<ref name="Uddin 342–347" /> For vehicles to power the grid cost-effectively, "smart meters" are essential.<ref name="Pillai" />

== See also ==
{{Portal|Energy|Renewable energy}}

{{Div col}}
* [[Charge control]]
* [[Charging station]]
* [[Distributed generation]]
* [[Power take-off]] (PTO) - combustion engine equivalent of [[V2L]] in [[Battery electric vehicle|BEV]]
* [[Electranet]]
* [[Electric vehicle battery]]
* [[Electricity meter]]
* [[Energy demand management]]
* [[Feed-in tariff]]
* [[Grid energy storage]]
* [[Grid-tied electrical system]]
* [[Load profile]]
* [[Load balancing (electrical power)]]
* [[Operating reserve]]
* [[Peaking power plant]]
* [[Power outage]]
* [[RechargeIT]]
* [[Smart meter]]
* [[Solid-state battery]]
* [[Vehicle-to-everything]] (V2X)
{{Div col end}}

==References==
{{reflist}}

==Further reading==
*{{cite web
 |url=http://www.nrel.gov/docs/fy15osti/63963.pdf
 |title=Multi-Lab EV Smart Grid Integration Requirements Study: Providing Guidance on Technology Development and Demonstration
 |first1=T.
 |last1=Markel
 |first2=A.
 |last2=Meintz
 |first3=K.
 |last3=Hardy
 |first4=B.
 |last4=Chen
 |first5=T.
 |last5=Bohn
 |first6=J.
 |last6=Smart
 |first7=D.
 |last7=Scoffield
 |first8=R.
 |last8=Hovsapian
 |first9=S.
 |last9=Saxena
 |first10=J.
 |last10=MacDonald
 |first11=S.
 |last11=Kiliccote
 |first12=K.
 |last12=Kahl
 |first13=R.
 |last13=Pratt
 |publisher=[[National Renewable Energy Laboratory]]
 |year=2015
 |access-date=2016-03-08
}}
*{{cite journal
| first = Stephen
| last = Diehl
| title = Study suggests electric cars could pay their owners back
| journal = Green Mountain College
| url = http://www.greenmtn.edu/news/V2G.asp
| archive-url = https://web.archive.org/web/20080225152521/http://www.greenmtn.edu/news/V2G.asp
| archive-date =2008-02-25
}}
*{{cite conference
 |first = Willett
 |last = Kempton
 |date = 2005-06-06
 |title = Automobiles: Designing the 21st century fleet
 |conference = Seattle V2G Technical Symposium, University of Delaware
 |url = http://www.sustainableballard.org/ev2g/pdf/Kempton-V2G-Designing-June05.pdf
 |url-status = dead
 |archive-url = https://web.archive.org/web/20060428215549/http://sustainableballard.org/ev2g/pdf/Kempton-V2G-Designing-June05.pdf
 |archive-date = 2006-04-28
}}
*{{cite book
| date= March 2003
| title = 20kW DC/AC Power Inverter Preliminary Specifications, For Distributed Power Applications
| publisher = UQM Technologies, Inc.
| url = http://www.uqm.com/products/specsheets/Power%20Inverter.html
| archive-url = https://web.archive.org/web/20080303222302/http://www.uqm.com/products/specsheets/Power%20Inverter.html
| archive-date =2008-03-03
}}
*{{cite book
| year =2000
| title =Reports, Papers, and Presentations
| via = AC Propulsion Inc.
| url = http://www.acpropulsion.com/resources/reports.htm
| isbn =978-0-7506-4636-9
| author =Heather Silyn-Roberts.
| publisher =Butterworth-Heinemann
| location =Oxford
| archive-url = https://web.archive.org/web/20081026120111/http://www.acpropulsion.com/resources/reports.htm
| archive-date=2008-10-26
}}

==External links==
*{{cite web
 |url=http://www.nrel.gov/transportation/project_ev_grid_integration.html
 |title=Electric Vehicle Grid Integration
 |publisher=[[National Renewable Energy Laboratory]]
 |access-date=2016-03-08
}}

{{Electric vehicles}}
{{Electricity generation}}

{{DEFAULTSORT:Vehicle-To-Grid}}
[[Category:Automotive technologies]]
[[Category:Electric vehicles]]
[[Category:Renewable energy economics]]
[[Category:Energy storage]]
[[Category:Sustainable energy]]
[[Category:Grid energy storage]]