EVs with two-way charging or bidirectional charging can be used to feed energy back into the electricity grid, power a house, and in case of an emergency or blackout, it can even provide backup power. Bidirectional chargers enable EVs to store solar power or cheap off-peak electricity to reduce household electricity costs. Whenever you are talking about bidirectional charging, the concept of V2G vs V2H vs V2L bidirectional charging is never missed. Let’s learn about this and things like what is a V2G bidirectional charger, what is a V2H bidirectional charger, etc in this blog.
What is Bidirectional Charging and How Does it Work?
Essentially, bidirectional EV charging is charging that occurs in two ways (back and forth). In this type of charging, the energy flows from the grid to the car or it can be used to power other devices or it can be sent back to the grid.
Just like a portable power that is used to charge your personal electronic devices, your car can also be used in the same way. In the case of EVs, they can charge much larger devices like your house, a barbeque, or even the electricity grid.
Bidirectional charging is an umbrella term covering several use cases. The most common use cases are V2G, V2H, and V2L. Now, let’s look at V2G vs V2H vs V2L Bidirectional Charging.
What is V2G vs V2H vs V2L Bidirectional Charging?
While talking about bidirectional charging, the concept of V2G, V2H, and V2L is much talked about. There is quite a difference between V2G vs V2H vs V2L bidirectional charging-
- V2G (Vehicle-to-Grid)- In this program, the EV exports the energy to the electricity grid to support it.
- V2L (Vehicle-to-Load)- In this type of arrangement, an EV can be used to charge other EVs or power other appliances.
- V2H (Vehicle-to-Home)- Here, EV energy is used to power a business or home.
What is a V2G Bidirectional Charger or V2G Bidirectional Charging?
In V2G or Vehicle-to-grid, a small portion of stored EV battery energy is exported back to the electricity grid when needed. This depends on the service arrangement. A bidirectional charger with a compatible EV is required to participate in the V2G program.
The EV owners who opt for this program are also given financial incentives. They are either given credits or their electricity cost is reduced. EVs enabled with V2G can also help their owners participate in a VPP(virtual power plant) program. It supplies power during peak demand hours and also improves grid stability.
Currently, only a handful of EVs have V2G and bidirectional DC charging capability. Some of the EVs that do support V2G include Mitsubishi Outlander or Eclipse plug-in hybrids and the later model Nissan Leaf (ZE1). With this, you should have understood what is a V2G bidirectional charger or V2G bidirectional charging.
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What is the Problem with V2G Bidirectional charging?
One of the major problems with V2G technology is the lack of standard bidirectional charging connectors and protocols. Additionally, there are regulatory challenges.
Vehicle-to-grid standards are complex and difficult as they involve regulating the safety, power, and electrical requirements when discharging energy into the grid. For bidirectional EV charging system equipment, UL9741 is a proposed safety standard that is still under development. It is built around the UL1741 (safety standard) and the IEEE1547 standard for interconnecting DER (distributed energy resources) with electrical power systems.
Nowadays, most EVs have standard CCS DC charge ports. Currently, Ford F-150 Lightning EV is the only EV that uses a CCS port for bidirectional charging. In the future, however, more EVs with CCS connection ports will be available with V2G and V2H capabilities. Now, let’s see what is a V2H bidirectional charger.
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What is a V2H Bidirectional Charger or V2H Bidirectional Charging?
Vehicle-to-home or V2H is quite similar to V2G. However, in this system, the power isn’t sent to the electricity grid but is used locally to power a home. This allows the EV to function like a regular household battery system and also helps increase self-sufficiency, especially when it’s combined with rooftop solar. But the most prominent benefit of V2H is its ability to supply backup power during a blackout.
To properly operate, V2H needs a compatible bidirectional charger and some additional equipment like an energy meter (CT meter). The CT meter is used to monitor energy flow to and from the grid. This is why the meter should be installed at the main grid connection point. When the system discovers the amount of grid energy consumed by your home, it signals the bidirectional EV charger to discharge an equal amount. It does offset any power drawn from the grid. Similarly, whenever this system detects energy being exported from a rooftop solar array, it diverts this energy to charge the EV. This is quite similar to the work of smart EV chargers.
To sanction backup power in the event of an emergency or a blackout, the V2H system needs to be able to detect the grid outage as well as isolate it from the network using an automatic contactor (switch). This is referred to as islanding.
Currently, only a few EVs have V2H technology. These EVs include Mitsubishi Outlander PHEV and the later model Nissan Leaf. Both these EVs use the older-style CHAdeMO connector. The new Ford F-150 Lightning EV is quite unique as it can use a CCS connector via an in-vehicle bidirectional charger to operate in V2H mode. However, there’s a catch, this EV model can only function when it’s used with the Ford Charge Station Pro along with the Ford Home Integration System. This made you understand what is a V2H bidirectional charger. Now, you must also be curious to learn what is a V2L charging and is V2L bidirectional.
What is a V2L Charging? Is V2L Bidirectional?
V2L or Vehicle-to-Load technology does not require a bidirectional charger to operate and thus is much simpler than the other two technologies discussed above. It s sometimes also called VTOL.
Vehicles with V2L come with a built-in bidirectional charger and standard AC power outlets, which can be utilities to plug in any usual household AC appliances. To provide power via a lead, there are also certain vehicles that use a special V2L adapter and the EV charging port. In case of an emergency, extension cords can be connected from the vehicle to the home to power essential loads, including computers, fridges, lighting, and even cooking appliances.
Via four 2.4kW AC power outlets for a total of 9.6kW of power, the new Ford F-150 Lightning has V2L capability. Other vehicles which have V2L technology are Kia EV6 and the new Hyundai IONIQ 5. These cars have both external and internal AC power outlets. This should have answered what is a V2L charging and is V2L bidirectional.
V2L for Off-Grid and Backup Power
While vehicles with V2L can be quite useful for backup power using extension leads to power selected appliances. You can also connect the V2L supply directly to a backup switchboard or even to the main distribution board using a particular AC transfer or change-over switch.
To reduce or even eliminate the need for a backup generator, a vehicle with V2L can also be assimilated into an off-grid solar power system. Most off-grid solar power systems have a bidirectional inverter charger. Technically, this charger is able to use power from any AC source, including a vehicle with V2L. However, to do so safely, the inverter would need to be installed as well as configured by a solar specialist or qualified electrician. This should have helped you understand V2G vs V2H vs V2L bidirectional charging.
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What are the 9 Best Bidirectional Chargers in the Market?
An advanced EV charger capable of two-way charging is referenced to as a bidirectional charger. It does sound simple, but it’s a quite complex power conversion process from alternating current (AC) to direct current (DC). This is the opposite of your regular unidirectional EV chargers that use AC to charge.
Bidirectional chargers aren’t like usual EV chargers and they operate similarly to inverters. They convert AC to DC during charging and then reverse during discharging. However, these chargers are only for vehicles compatible with two-way DC charging. The best bidirectional chargers in the market are as follows-
1. Wallbox Quasar
The Wallbox Quasar is a bidirectional charger that is the smallest of its kind. It is in fact the first EV charger that was designed for the home. It provides advanced two-way DC charging capabilities.
This charger has a maximum power rating of 32A or 7.4kW. However, you should note a point that it’s only compatible with vehicles that have a CHAdeMO DC vehicle connector. Currently, it can only be used with the Mitsubishi Outlander plug-in hybrid and the later-generation Nissan Leaf EV. The Wallbox Quasar can cost anywhere around US$4500 to $8000 (depending on the local taxes and the country).
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2. Rectifier Technologies Highbury
Rectifier Technologies is an Australian power conversion equipment manufacturer. It is the second company in the world to develop a two-way compact residential charger. Although the Highbury bidirectional DC charger isn’t yet on the market it still claims to be 96% efficient and features quite a modern as well as slim design. The company claims that this charger will be the world’s slimmest bi-direction DC charger. It will have a standard 7kW, a high power 11kW (46A), and will be available in two sizes.
Initially, via V2G, it will enable the EV owners to sell excess power to the grid. However, additional functionality like V2H (Vehicle-to-Home) will be available at a later stage. It will be compatible with both CSS or CHAdeMO-compliant electric vehicles. Its pricing isn’t also yet available.
3. Wallbox Quasar 2
Recently, Wallbox announced the second generation Quasar 2. This new bidirectional DC charter has been designed from the ground up. It now offers up to 48A or 11.5kW of discharging or charging power. Its styling is also completely different from the previous model. The earlier model had an unconventional look with no display. However, the new Quasar 2 comes with a blackout mode which allows a compatible vehicle to power homes in case of power outages.
Wallbox claims that this charger can smoothly transition your home from grid supply to vehicle supply. This means that it works in order with an external grid isolator (contractor) which is needed to safely island your home from the grid. Its full specification has not been released yet and thus its pricing is also not yet available. Although, the company website indicates that this charger will contain a vast array of communication options including Bluetooth, WiFi, Ethernet, and even 3G/4G.
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4. Emporia V2X bi-directional charger
Emporia is a small Colorado-based company that has developed the V2X home bidirectional charger. This charger is quite impressive as it features an integrated silicon-carbide-based AC/DC inverter (designed by BREK Electronics). It is rated at a maximum of 11.52kW or 48A. It can be coupled with the Emporia Vue home energy management system and is compatible with CSS Type 1 connector to automate your storage needs and energy use. Its most noticeable feature is that it has off-grid islanding support. It will function in an off-grid mode with the addition of a compatible grid isolation device (contractor).
Its price is around US$1500 and thus it is one of the most affordable universal bi-directional chargers. This product is however still in the design phase and will release sometime time in 2023.
5. Delta V2H bidirectional charger
Delta Electronics is a company that specializes in power conversion and energy efficiency equipment, including energy storage and solar. This company has produced a range of bidirectional EV chargers for residential and commercial applications.
The Delta V2H is a 3-phase vehicle-to-home (V2H) bidirectional charger that is available in two models rated at 22kW or 11kW. The charger can operate in off-grid (backup) and on-grid modes. However, this charger is currently only compatible with CHAdeMO vehicle connectors. It also offers a high operating efficiency of 95%. A 6kW single-phase version of this charger is also in development, but lesser details are known about it till now.
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6. Fermata Energy FE-15
The FE-15 bidirectional charger is produced by Fermata Energy which is a US-based company founded in 2010. It is one of the most powerful two-way DC chargers available in North America. It has a 15kW charge as well as a discharge power rating. Currently, this charger is only compatible with vehicles with a CHAdeMO DC connector. Based on the specifications and aesthetics, this wall-mounted charger is clearly designed for durability, safety, and performance.
This charger is also UL9741 certified. Currently, in the US, it is the only DC charger certified for use with the Nissan LEAF. Its parent company has also developed a more powerful 3-phase 20kW bidirectional charger that can be used with small commercial electric vehicles.
7. Autel MaxiCharger V2X
Autel Energy is a US-based company that was established in 2004. It specializes in intelligent automotive services and products. Over the years, the company has been involved in the development of high-quality home EV chargers, commercial EV charging solutions, and a range of fast DC chargers.
Autel MaxiCharger V2X is a high-power 12kW bidirectional charger that offers both V2H and V2G functions or vehicle-to-everything, hence the term V2X. It will be available with either CHAdeMO or CCS1 and offers a wide range of communication options, including ethernet, CAN, WiFi, Bluetooth, OCPP 1.6J communication protocol, and RS485. Most noticeably, its CCS1 version operates with a varying DC voltage range from 150 to 950V DC. This means it will be compatible with vehicle platforms having newer high-voltage. Its official release date and pricing are still unknown.
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8. Enphase bidirectional EV charger
Enphase Energy is a leading solar microinverter manufacturer in the world founded in 2006. The Enphase bidirectional EV charger is built around the IQ8 microinverter technology, which enables both V2H and V2G functionality. This feature makes it quite unique. The IQ8 microinverters are actually micro-bidirectional inverters that can operate in off-grid and on-grid modes.
This charger is ideal for building a bidirectional charger. Additionally, it also enables smooth integration into the Enphase home energy ecosystem. The bidirectional charger is quite similar to the Enphase Encharge battery system, however, in the case of the EV charger, the battery is inside the vehicle.
Enphase hasn’t yet released the full specifications of this charger. Based on the limited information available about it, the charger seems quite similar to the Encharge 10 battery system. It will most probably release in 2024.
9. Ford Charge Station Pro
The Charge Station Pro is a Ford-exclusive EV charger. It is rated at a maximum of 19.2kW (240V) or 80-Amps. It was released along with the new Ford F-150 Lightning Electric Pickup around mid-2022. Ford collaborated with Siemens eMobility to develop this charger. It will allow the F-150 EV to power a home and when installed together with the Home Integration System, it will provide up to 9.6kW of power to enable intelligent backup power.
It isn’t still clear how this charger will function in regards to the power conversion. However, it seems that the charger can operate as either an AC bidirectional system using the EVs internal charger for bidirectional power conversion or a regular AC charger using the US standard J1172 connector (J plug). Therefore, this charger doesn’t have an in-built inverter like the other chargers mentioned in this list.
The official price of the Ford Charge Station Pro is around US$1310 plus installation. However, the pricing for the Ford Home integration System is not yet available.
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How Can You Benefit From Bidirectional Charging?
There are three main benefits of bidirectional charging are-
1. Make Money
V2G allows you to make money by providing services to the electricity grid. Your energy provider would discharge your battery when the demand is high and charge it when the demand is low. Depending on the duration and type of service provided, you would be paid an agreed rate.
2. Save Money
It’s a given that the ongoing costs of owning an electric car are noticeably lower than a petrol car. This is due to lower servicing, maintenance, and fuel costs.
With bidirectional charging, you’ll have the option to lower your electricity by sending energy from the car battery to your home (V2H). To reduce your electricity bill, you can employ load shifting just like stationary batteries.
Load shifting will reduce your electricity bill by charging discharging when the energy is expensive and charging when it’s cheap. The main downside of using a V2H is that you’ll always need to be plugged into the compatible bidirectional charging wallbox.
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3. Energy Independence
It is one of the major benefits of bidirectional charging. Bidirectional charging eliminates or reduces your reliance on grid electricity. However, it is quite unlikely that the bidirectional charging allows you to do completely off-the-grid. But it will significantly reduce the amount of grid energy you use.
Will Bidirectional Charging Result in More EV Degradation?
Similar to the battery in your phone, every time an EV uses energy, there is a scarcely detectable amount of degradation. In addition to everyday driving, if you also use your car as energy storage, there will be an increase in the number of cycles(a full charge and discharge). Theoretically, this will increase the degradation of your battery.
There is some evidence that suggests that compared to driving, bidirectional discharging is less demanding on the battery. More heat is produced by the power volatility and intensity from driving in comparison to the lower constant load from bidirectional use.
With this, you have learned all the crucial points about bidirectional charging, its benefits, and most importantly the comparison of V2G vs V2H vs V2L bidirectional charging.
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