Bidirectional Charging - A Complete Guide
Besides being an alternative to fossil fuels, EVs are about to change how we power EVERYTHING.
Did you know that you can actually earn money from your EV by merely charging it?
It's called bidirectional EV charging.
If you haven't heard about it, don't fret. We're here to help you understand what it is.
There are numerous articles filled with technical buzzwords that will get you even more confused.
In this blog, we'll explain how bidirectional charging works and lay down the different benefits EV drivers can get.
What is bidirectional charging?
In simple terms, bidirectional charging is done in two ways.
While the usual unidirectional EV charger only allows electricity to flow from the grid to electric vehicles, a bidirectional EV charger allows electricity to flow both ways.
This means your electric vehicle can actually send power back to the grid or supply power to your home.
How does bidirectional work?
When charging an EV, alternating current (AC) from the electricity grid is converted into direct current (DC) before being supplied to the EV batteries.
This conversion is done by the on-board charger or a converter built into the charger.
Then, the DC power stored in the batteries is converted back to AC electricity to be either used to power appliances in your house or sent back to the power grid - giving you bidirectional charging.
A bidirectional charger will typically have an internal converter, which means it can do the electrical conversion process independently.
They can even regulate the amount of power supplied to or drawn from the EV's batteries.
What are the different types of bidirectional charging?
Vehicle to Grid (V2G)
Vehicle to Grid technology or V2G is when a bidirectional DC charger is used to provide power to the grid from the car batteries, by converting DC electricity to AC electricity with a built-in converter.
V2G can be especially helpful during peak demand hours when the utility grid experiences an unusually high energy demand.
The system allows electric vehicles to charge during off-peak times (usually at night) and provide backup power to the electric grid during the daytime.
If you think about it, for most of the day, EVs usually just sit idle in parking spaces.
Given the proper infrastructure, EVs that are parked and charging could serve as large-scale power banks to stabilize the grid when it's under stress.
This way, power outages could become a thing of the past in the near future.
Vehicle to Home (V2H)
Vehicle to Home or V2H is when bidirectional EV chargers supply power from an EV's battery to a house, or possibly, other buildings.
A built-in power converter converts the energy stored in the EV batteries from DC to AC to power an entire home or building.
Just like V2G, V2H could be incredibly helpful in maintaining the balance in the grid.
For instance, by charging your EV at night during off-peak hours, not only are you getting special energy prices from utility companies, but you also get enough energy stored in your car battery, which you can use to power appliances during the day.
This ensures you have enough power in your home and also reduces pressure on the grid during peak periods.
The Nissan Leaf is one of the most common EVs with the V2G feature.
Vehicle to Load (V2L)
Vehicle to Load or V2L is probably the most common of the bidirectional charging systems.
V2L two-way charging allows you to use your car's battery to power appliances and tools on the go.
V2L charging relies on EVs with a built-in converter and 120-volt plug.
The Hyundai Ioniq 5, for example, relies on a V2L adapter to be able to provide energy to appliances.
Vehicle to Vehicle (V2V)
Vehicle to Vehicle or V2V charging allows you to transfer power from one electric vehicle to another.
This is especially helpful when you're on a caravan and someone in the group runs out of juice.
EVs with bidirectional charging
While there are several potential benefits of bidirectional charging, EVs possessing this capability today still remain limited.
Here's a limited list for your reference:
- BYD Atto 3
- BYD Han EV
- Ford F-150 Lightning
- Hyundai Ioniq 5
- KIA EV6
- MG ZS EV (2022)
- Nissan Leaf ZE1
- Outlander PHEV
- VW ID Models
What are the benefits of bidirectional charging?
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Save money. Bidirectional charging can help you save on utility costs by using low-priced energy during peak hours. By using bidirectional chargers to charge your EVs during off-peak hours, you have access to discounted energy stored to power your home during the day, when energy costs are affected by high demand.
You can also use renewable energy like solar panels to charge your EVs and then use that energy to power your home.
With the Vehicle to Grid technology, you can also sell energy back to utility companies for redistribution. - Backup power. Bidirectional charging can turn your EV battery into a backup power source during outages. A typical EV battery holds around 60 kilowatt-hours of electricity, which is enough to power an entire home for 2 straight days.
- Portable power source. With the Vehicle to Load (V2L) and Vehicle to Vehicle (V2V) technology, you can turn your EV's battery into a portable power bank for appliances, tools, and even other EVs.
What's the difference between bidirectional charging and smart charging?
Smart charging can either be unidirectional or bidirectional, allowing you to control the charging time and rate using a smart device instead of a manual on/off button.
This is possible because of the data connections between the EV and the smart charger.
With smart chargers, EVs can be plugged in without necessarily having to be actively charging.
Instead, EV owners or utility companies get to decide when it's best to charge, relative to the demand and cost.
FAQs
What is bidirectional charging? And what does it have to do with V2G?
Bidirectional charging allows electricity to flow from the grid to the EV battery and vice versa. V2G stands for Vehicle to Grid, which means the energy from the vehicle is returned to the electricity grid.
What's the current status of bidirectional charging?
With the increasing power, energy efficiency, and energy storage capabilities of EV batteries, bidirectional charging is seen to become the answer to a more sustainable future.
Is bidirectional charging becoming more accessible?
As of the moment, bidirectional charging is limited to a number of electric vehicles. But this emerging technology will soon become one of the most imperative features in an EV.
How does EV bidirectional charging work?
When charging an EV, alternating current (AC) from the electricity grid is converted into direct current (DC) before being supplied to the EV batteries.
This conversion is done by the on-board charger or a converter built-in to the charger.
Then, the DC power stored in the batteries is converted back to AC electricity to either be used to power appliances in your house or be sent back to the power grid.
Are Tesla batteries bidirectional?
Currently, Tesla batteries are not bidirectional. But Tesla CEO Elon Musk recently announced that the technology would be available in the next 2 years.
What cars can do V2H?
As of writing, only a handful of EVs can do V2H, including the Nissan Leaf and the Mitsubishi Outlander PHEV, both using the older CHAdeMO connector.