Cars on a roadway
Katie Pyzyk

Thanks for sharing: Peer-to-peer power network could charge EVs on the go

Drivers consistently cite range and charging time as concerns holding them back from purchasing an electric vehicle. A new study suggests a novel solution that harnesses EVs’ bidirectional power flow: two nearby EVs wirelessly sharing energy while in motion to prevent the need to stop for a charge.

A figure from the study published in Scientific Reports illustrates a proposed peer-to-peer wired charging scheme for moving vehicles.
A figure from the study published in Scientific Reports illustrates a proposed peer-to-peer wired charging scheme for moving vehicles. Credit: Credit: Chakraborty, P., Parker, R., Hoque, T. et al.

From cloud to car

Under this model, a cloud-based control system gathers and analyzes traffic and EV battery information to update a charge distribution map as charging requests come in. The system chooses two nearby vehicles to pair and locks their speed in sync to allow seamless charging. The researchers envision vehicle charging via two methods: a flexible, wired charger controlled by autopilot that runs between the cars, or a drone charger.

Figures illustrate the dual battery setup under the proposed charge-sharing scheme: The smaller, faster battery can be used for peer-to-peer charge transfer and, once detached, can recharge the slower main battery.
Figures illustrate the dual battery setup under the proposed charge-sharing scheme: The smaller, faster battery can be used for peer-to-peer charge transfer and, once detached, can recharge the slower main battery. Credit: Chakraborty, P., Parker, R., Hoque, T. et al.

Vehicles participating in this network would use power from different internal batteries at different times. Smaller, faster-charging batteries would transfer charge between vehicles, and slower, larger batteries would be used for the vehicle’s prolonged operation. 

When the vehicles complete their charging cycle, they unpair and the charge within their own two batteries redistributes for normal operations. The dual-battery setup boosts efficiency and reduces the amount of time the vehicles must remain tethered to charge. 

Further, the researchers suggested developing mobile charging stations, or vehicles with a large battery that are deployed to charge a network of vehicles. Outfitting the mobile charging hubs to run on solar power or other renewable energy sources could provide a 68% reduction in carbon emissions compared with EVs charged from the grid, which currently primarily relies on energy generated from coal, natural gas, and oil.

Figures illustrate charge sharing scenarios. At left, a mobile charging station powers electric vehicles on the go. At right, a mobile charging station "leader" recharges an electric vehicle platoon.
Figures illustrate charge sharing scenarios. At left, a mobile charging station powers electric vehicles on the go. At right, a mobile charging station “leader” recharges an electric vehicle platoon. Credit: Chakraborty, P., Parker, R., Hoque, T. et al.

Share the wealth

A University of Kansas assistant professor of electrical engineering and computer science is on the project team that proposed the peer-to-peer charging system. He explains a potential financial boon for EV drivers who share their charge, which would create a mutually beneficial system.

“One car might have abundant charge, and it may not need to go too far, and it can sell its charge to another car — so there’s an economic incentive,” Tamzidul Hoque said in a news release. “The other car, which is traveling a long way, doesn’t have much charge, and not having to stop for recharging would shorten their journey by several hours.”

The peer-to-peer concept would work well for EV fleets, the researchers say, especially in truck platooning, when trucks travel together in a pack and often are connected wirelessly by a computer communication system. It would also provide better charging access in regions with little or no charging infrastructure.