This group brings together the best thinkers on energy and climate. Join us for smart, insightful posts and conversations about where the energy industry is and where it is going.


Bidirectional Charging Sparks Excitement for EV Owners

image credit:
Emily Newton's picture
Editor-In-Chief, Revolutionized Magazine

Emily Newton is the Editor-in-Chief at Revolutionized Magazine. She enjoys writing articles in the energy industry as well as other industrial sectors.

  • Member since 2020
  • 36 items added with 27,801 views
  • Apr 22, 2022

A significant portion of greenhouse gas emissions comes from the transportation sector. In response, eco-consumers are investing in electric vehicles (EVs) to target pollution. Environmental engineers are increasing global infrastructure’s compatibility with EVs by advancing charging technologies.

Conventional unidirectional chargers have economic and environmental limitations. In response, engineers identified these challenges and developed bidirectional charging advancements. This new technology offers various benefits to EV owners.

Sustainability Limitations of Unidirectional Charging

Unidirectional charging is an outdated energy distribution practice that caters to properties unable to produce power independently.

Today, people can generate electricity on-site with solar, geothermal and wind power, but unidirectional charging systems prevent them from delivering excess energy back to the grid. Individuals may waste power when they have fewer items to charge because renewable energy is difficult to store.

Residential storage systems are expensive and hard to obtain. Bidirectional technologies eliminate the need for large-scale batteries by distributing excess electricity to other devices and the grid. Using advanced power distribution systems can support grid decarbonization efforts.

Bidirectional Charging for Clean Transportation

Eco-consumers expect their EVs to make a significant environmental impact. Conventional charging methods contribute to global greenhouse gas emissions. Nearly 61% of America’s electricity supply comes from fossil fuels.

EV drivers can shrink their carbon footprints by using solar power for charging. Bidirectional chargers help people deliver excess renewable power back to the grid and other appliances. Efficiently distributing clean energy may help community members decarbonize their grids.

Energy professionals can also increase EV charging sustainability by utilizing existing infrastructures. Some developers are converting old phone booths into charging stations to reduce material waste. Irish energy producers are converting nearly 180 booths into EV chargers, increasing accessibility and efficiency.  

Some renewable energy sources like solar power have low efficiency rates, but people can optimize their power supplies by adopting compatible distribution technologies. Advancing distribution systems can support sustainability initiatives.  

Technology Supporting the V2G Initiative

Bidirectional charging significantly reduces energy waste. Residents can feed excess power to the grid and support decarbonization efforts. Developed countries like the U.S. are using different technologies to meet sustainability goals.

Vehicle-to-grid (V2G) energy distribution helps regions access enough power to meet consumers’ needs. Energy professionals also use information technology (IT) and operations technology (OT) to optimize supplies. The technologies monitor power distribution systems and predict outages.

Optimizing V2G systems using bidirectional charging can improve grid sustainability. It also enhances its compatibility with renewable energy sources. Residents that charge their EVs with solar can deliver excess power to local grids.

Using vehicles as mobile battery packs can decrease society’s reliance on fossil fuels. People may also use bidirectional charging systems to power their homes, shrinking their carbon footprints.

Using EV Charging to Power Homes

People can also engage in vehicle-to-home (V2H) exchanges when using bidirectional chargers. Investing in renewable energy systems can make the most of optimal power-sharing. Bidirectional chargers work with direct current converters within EVs to deliver electricity back into a home.

Residential properties consume nearly 21% of America’s power supply. Homeowners can minimize their reliance on fossil fuels by producing and using renewable energy. Distributing power back to a home after an EV reaches a full charge may improve residents’ environmental and economic stability.

Using renewable power to charge EVs and household appliances can support net-zero properties. These homes use as much energy as they produce, creating a sustainable balance. They waste zero electricity and distribute additional power to the grid.

Individuals may build net-zero homes by connecting solar panels to EV chargers. They can use bidirectional chargers to filter excess solar power into homes and lower utility costs.  

The Economic Benefits of Bidirectional Charging

EV drivers are excited about new bidirectional charging technologies because of their economic benefits. Creating a decarbonized power grid requires diverse energy sources. The power sector may rely on residential energy production to meet consumers’ demands.

Residents can sell their solar power to the grid using bidirectional charging technologies. Selling excess electricity provides a source of passive income. 

Using renewable energy to power a whole home also increases economic savings. Solar is currently the most affordable energy source on the market. Residents can avoid energy cost increases by reducing their reliance on fossil fuels.

The Environmental Benefits of Bidirectional Charging

Bidirectional charging also minimizes adverse ecological effects. Their compatibility with EVs and renewable energy sources reduces greenhouse gas emissions. EVs produce zero tailpipe emissions while operating.

The chargers additionally reduce energy waste, eliminating unnecessary emissions. Americans waste nearly two-thirds of their power supplies annually. Optimizing residential energy use could effectively shrink the national carbon footprint.

Bidirectional charging supports regional clean energy regulations. Communities that decarbonize their power grids may rely on residents to produce renewable energy.

Future-Proofing Homes

The Biden-Harris administration has ambitious sustainability goals for the U.S. and plans to reach carbon neutrality by 2030. Government officials may ban some energy sources and appliances to reach the goal.

People can abide by the administration’s demands by adopting EVs and installing bidirectional charging systems to optimize their energy consumption. Adding sustainable technologies to a home can protect residents’ health and well-being.

Vehicles and energy sources producing emissions on-site contribute to health problems. People risk developing lung cancer, asthma and other respiratory illnesses in high pollution regions. Using EVs and renewable energy lowers local emissions.

Future-proofing a home with sustainable technologies increases its market success. It also increases the value of a property, helping homeowners gain higher returns on their investments. Few properties have bidirectional chargers, so installing one could impress eco-conscious buyers.

When Will Bidirectional Chargers be Widely Accessible?

Bidirectional charging is a new technology, and few manufacturers are producing these chargers. However, eco-consumers’ interest is increasing production demands. More people will be able to access chargers’ economic and environmental benefits are they hit the consumer market.

More EVs also increase the demand for bidirectional chargers. Regions’ decarbonized electricity goals influence technological advancements, and market researchers believe sustainable chargers will be readily available in the coming years

Benoit Marcoux's picture
Benoit Marcoux on Apr 25, 2022

v2G is a bit more complicated than this article makes it.

V2G should be distinguished from the Vehicle-to-Home (V2H) and Vehicle-to-Load (V2L) use cases, as V2H and V2L do not feedback power to the electrical grid to relieve grid constraints or optimize customer rates.

  • V2H is analogous to using the EV battery as a standby generator for use during a power outage. A V2G vehicle, when coupled with a home energy management system, may also offer V2H.
  • V2L is like using a portable generator to power tools at a construction site or a home refrigerator during a power outage. V2G vehicles may or may not have plugs for V2L, although this is an increasingly common EV feature.

V2G and V2H or V2L have different power electronics and standards to meet. V2H and V2L are easier to implement as they do not have to meet grid connection standards, while V2G systems must meet DER interconnection standards. An example is Rule 21 in California which makes compliance with IEEE 2030.5 and SunSpec Common Smart Inverter Profile (CSIP) standard mandatory distributed energy resources.[i] On the other hand, a V2H or V2L vehicle (or its supply equipment) needs to have a grid-forming inverter, while a V2G inverter acts as a grid-following power source.[ii] [iii]

On-Board V2G (AC) vs. Off-Board V2G (DC)

Electrically, V2G (and V2H) may come in two varieties: on-board V2G (AC) and off-board V2G (DC).[iv]

On-Board V2G (AC)

With on-board V2G, the EV exports AC power to the grid, through a home EV supply equipment. For light-duty vehicles, the connector is SAE J1772; SAE J3072 defines the communication requirements with the supply equipment. The supply equipment needs to be bidirectional and to support the appropriate protocol with the vehicle and compatible with the local grid connection standards.

However, for V2H with an on-board inverter, a balancing transformer and transfer switch must be added to the residential circuit. This is because the standard Type 1 SAE J1772 plug used in North America is a single-phase plug and does not have a dedicated neutral wire for the split phase 120/240 V service used in homes. The J1772 plug can be used for V2G (feeding back to the grid at 240 V) but can’t be used directly for split phase 120/240 V V2H without the balancing transformer and transfer switch.

Many EVs come with additional plugs, in addition to J1772, for 120/240 V V2L applications. Examples included the NEMA 5–15 120 V plug (the common residential plug) and the twist-lock L14-30 split phase 120/240 V plug (often seen on portable generators). The Hyundai IONIQ 5[v] and the GMC Hummer EV[vi] are examples of vehicles with additional plugs.

As of this writing, commercially available EVs in North America do not support on-board V2G, but some have been modified to test the concept for pilot programs.[vii] However, many automakers have announced vehicles with bidirectional chargers, and possibly AC V2G, although there are little publicly available specifications.

Off-Board V2G (DC)

With off-board V2G, the EV exports DC power to a bidirectional DC charger.

Bidirectional charging has been supported by the CHAdeMO DC fast-charging standard for quite some time, and the Nissan Leaf has offered the feature since 2013[viii]. Several light-duty DC V2G pilots therefore used these vehicles. However, with the new Nissan Ariya electric crossover using CCS instead of CHAdeMO, Nissan effectively made CHAdeMO a legacy standard in North America.[ix]

CCS is an alternative for off-board V2G, but, unfortunately, CCS does not yet support bidirectional charging. CharIN[x], the global association dedicated to CCS, is developing the standards for V2G charging[xi]. The

ISO 15118-20 standard was approved the first quarter of 2022 and will include bidirectional charging. This will mark the official start of interoperability testing. However, it will take time to reach mass-market adoption since the new standard needs to be implemented and tested beforehand to overcome potential malfunctions on software and hardware side.[xii] BMW, Ford, Honda, and Volkswagen have all announced plans to incorporate bidirectional charging and energy management, with an implementation target of 2025, but it is not clear if this is for V2G AC or V2G DC.[xiii]

A critique of off-board V2G is the high cost of bidirectional DC chargers.[xiv] A solution may be to combine the bidirectional charger with a solar inverter, integrating power electronics for residences with both solar panels and EV charging. The dcbel r16 is an example of such an integrated approach[xv], combining a Level 2 EV charger, a DC bidirectional EV charger, MPPT solar inverters, a stationary battery charger/inverter and a home energy manager in a package that costs less than those components purchased individually.[xvi]


[i]        See, accessed 20211006.

[ii]       See, on page 9, accessed 20211208.

[iii]      “EV V2G-AC and V2G-DC, SAE – ISO – CHAdeMO Comparison for U.S.”, John Halliwell, EPRI, April 22, 2021.

[iv]       See, accessed 20211008, for an in-depth discussion of on-board and off-board V2G.

[x]        See, accessed 20211008.

[xii]      Emails received from Ricardo Schumann, Coordination Office, Charging Interface Initiative (CharIN) e.V., 20211015 and 20220119.

[xv]      See, accessed 20211012.

[xvi]     See, accessed 20211210.

Jim Stack's picture
Jim Stack on Apr 25, 2022

Some of the new vehicles already have V2G built into them. The Lucid with 500 mile range made in Casa Grand Arizona has V2G. The FORD F0150 Lightning has V2G as well as others. 

    Next you need a EVSE also called a car charger that can take power to charge as well as send power out to the home or GRID depending on need. 

    Last you need an agreement like we have for Solar so you can use and sell electric back to the GRID. If you plan to power your home during an outage you also need a automatic disconnect switch so you don't try to power up the GRID. 

     This has already been done at the University of Delaware for over 10 years. They used ACPropulsion electric vehicles that have had this feature in all of their cars. 

Emily Newton's picture
Thank Emily for the Post!
Energy Central contributors share their experience and insights for the benefit of other Members (like you). Please show them your appreciation by leaving a comment, 'liking' this post, or following this Member.
More posts from this member

Get Published - Build a Following

The Energy Central Power Industry Network is based on one core idea - power industry professionals helping each other and advancing the industry by sharing and learning from each other.

If you have an experience or insight to share or have learned something from a conference or seminar, your peers and colleagues on Energy Central want to hear about it. It's also easy to share a link to an article you've liked or an industry resource that you think would be helpful.

                 Learn more about posting on Energy Central »