Does NACS Support Bidirectional Charging?

Bidirectional charging allows EVs to not only receive power from the grid for charging but also to send power back to the grid or power external devices through a two-way connection.

This feature enables EVs to serve as energy storage devices, potentially helping to balance electricity supply and demand on the grid. For example, during peak demand periods, EVs can discharge stored electricity back to the grid, reducing strain on the grid and potentially earning revenue for vehicle owners through grid services. Conversely, during periods of low demand or when renewable energy sources like solar or wind are abundant, EVs can charge up, storing excess energy for backup power.

Traditional EV chargers convert alternating current (AC) from the grid into direct current (DC) for storage in the EV's batteries. With bidirectional charging, this stored DC power can be converted back into AC electricity when needed, allowing it to provide power to household appliances or be returned to the grid. Bidirectional EV chargers are equipped with internal converters that manage this conversion process and regulate the flow of power to and from the EV's batteries.

There are four types of bidirectional charging:

1. Vehicle to Grid (V2G):
   • Electric cars supply power back to the electrical grid during peak demand periods.
   • Acts as distributed energy resources, reducing strain on the grid and enhancing stability.
2. Vehicle to Home (V2H):
   • Bidirectional chargers provide backup power to homes during power outages.
   • Energy stored in EV batteries is transferred directly to essential appliances and systems.
3. Vehicle to Load (V2L):
   • EVs function as mobile power sources for external devices or loads.
   • Enhances practicality and resilience in scenarios like camping or emergencies.
4. Vehicle to Vehicle (V2V):
   • Allows direct energy transfer between EVs.
   • Optimizes resource utilization within the EV fleet, similar to gas-powered cars jump-starting each other's batteries.

Will NACS Support Bidirectional Charging?

Tesla has shown little interest in bidirectional charging despite its rivals Ford, Rivian, Hyundai, and Kia releasing their versions of V2L-capable EVs. Tesla Senior Vice President for Powertrain and Energy Engineering Drew Baglino said in an interview that the decision to not include the feature in their EVs is a matter of prioritizing what would "give consumers more for less".

Interestingly, the aforementioned carmakers were some of the first to announce they were adopting Tesla's connector even before its official standardization.

At the 2023 Tesla Investor Day, Baglino shared that, beginning in 2025, all Tesla vehicles will have bidirectional charging capabilities added to their arsenal. However, the company's highly-anticipated Cybertruck had already debuted with Powershare--its version of bidirectional charging. With Powershare, the Cybertruck, which has a 122.4 kWh capacity, has a maximum continuous output of 11.5 kW, and can consistently provide 9.6 kW through five outlets.

Ford

The Ford F-150 Lightning Truck currently relies on the Ford Charge Station Pro, a bi-directional home charging station with up to 80 amps of maximum current. With Ford's intelligent Backup Power feature, the F-150 Lightning can send surplus power back to power a home, another vehicle, or virtually any device it can plug into. Ford recommends to have its Home Integration System installed together with the home energy station for up to 9.6 kW of output. Despite not having DC fast charging capabilities, the Charge Station Pro uses the CCS1 connector to charge the F-150.

While Ford announced its NACS adoption, the company has not confirmed whether it would be the sole connector used for all its models, and instead said its "fleet will include a mix of port configurations". If Ford is to keep the F-150's two-way charging capabilities, it will have to work with Tesla to configure the NACS and the vehicle accordingly.

Rivian

In a recent interview, Rivian CEO RJ Scaringe bared that the R1T and R1S have "hidden" bidirectional charging capabilities waiting to be unlocked by a simple software update. This will allow the vehicles to supply power to external sources, such as a house or another vehicle, using a 240V inverter similar to Ford's Pro Power or Tesla's CyberTruck. Additionally, Rivian plans to integrate a 240V AC output option into future models, enhancing their utility for powering household appliances and devices. While the current models already feature standard 110V electrical outlets, the CCS charging port will provide the higher power output necessary for more significant applications.

Despite the first NACS-compatible non-Tesla EVs not being due until 2025, the Rivian R2, R3, and R3X all sport the NACS receptacle, only, on the rear right side, which means owners have to block two parking slots and walk around the vehicle to use Tesla's Superchargers.

Hyundai

Hyundai's IONIQ 5 and IONIQ 6 were among the first EVs to feature a vehicle-to-load (V2L) capability. Using a dedicated V2L adapter, the IONIQ can supply AC power up to a maximum of 3.6kW, enough to power small appliances such as laptops, smartphones, power tools, and camping equipment. The adapter features a J1772 receptacle on one end and a NEMA 5-15 outlet at the rear.

Since the IONIQ line uses the J1772 and CCS1 connectors for charging, Hyundai's impending shift to the NACS connector raises the question of whether its V2L capabilities would continue with different technology.

California May Force Tesla to Implement V2X

One reason many believe Tesla is not prioritizing the V2X feature is because of its ancillary business, Powerwall. The Powerwall is a rechargeable lithium-ion battery that stores energy from solar power and the grid, serving as backup power for homes during outages. However, Tesla may be forced to implement the V2X feature soon.

While the two-way charging capabilities of early NACS adopters are still up in the air, a bill in the California legislature, SB 233, is aiming to require bidirectional charging capability for all EVs sold beginning in 2027 and after. State Senator Nancy Skinner cited the potential of EV batteries as mobile energy storage units, serving as backup power to households during blackouts. California is used to rolling blackouts during peak demand periods, particularly during the months of August and September when heatwaves are common. The bill also seeks to increase funding for bidirectional infrastructure and promote interoperability testing to facilitate widespread adoption.

FAQs

• Which EV offer bidirectional charging?

  The Ford F-150 Lightning, Rivian R1T/R1S, Hyundai IONIQ 5/6, and the Nissan Leaf ZE1 have bidirectional charging capabilities. These vehicles can send power back to power a home, another vehicle, or virtually any device they can plug into.

• What chargers are bidirectional?

  The Wallbox Quasar, Emporia V2X, Fermata Energy FE-20, and the Ford Charge Station Pro are some of the bidirectional chargers on the market.

• Can CCS do V2G?

  Yes, CCS (Combined Charging System) can support Vehicle-to-Grid (V2G) functionality. EVs equipped with CCS connectors, such as the Ford F-150 Lightning and Rivian R1T/R1S, can utilize bidirectional charging capabilities to supply power back to the grid during peak demand periods.