Argonne Leads DOE's Effort to Evaluate Plug-in Hybrid Technology

Argonne’s Advanced Powertrain Research Facility (APRF) enables researchers to conduct vehicle benchmarking and testing activities that provide data critical to the development and commercialization of next-generation vehicles such as PHEVs.

Argonne's Research

Argonne National Laboratory is the U.S. Department of Energy's lead national laboratory for the simulation, validation and laboratory evaluation of plug-in hybrid electric vehicles and the advanced technologies required for these vehicles.

What is a Plug-in Hybrid?

A plug-in hybrid electric vehicle is similar to the hybrid electric vehicles (HEVs) on the market today, but it has a larger battery that is charged both by the vehicle's gasoline engine and from plugging into a standard 110 V electrical outlet for a few hours each day. PHEVs and HEVs both use battery-powered motors and gasoline-powered engines to get high fuel efficiency, but PHEVs can further displace fuel usage with off-board electrical energy charged at home.

PHEV Challenges

Energy Sources

While a PHEV might be less costly for the consumer to drive than a gasoline-powered vehicle, it draws power from the electrical grid when charging. Virtually all electricity in the United States comes from domestic energy sources. In some areas, much of that electricity is generated by coal-burning power generation plants. The energy costs to extract and transport the coal, as well as the environmental considerations associated with burning the coal, are all part of the overall cost of using plug-in technology. These issues decrease in importance as the amount of renewable energy in the electricity mix increases. There is also the question of how used batteries will be recycled, and how much that recycling will cost on a per-vehicle basis once all transport, processing, and disposal costs are considered.

Cost

PHEVs require additional, expensive components. Very large, heavy, and costly batteries are required to provide vehicle range. Also, power electronics need to be made smaller, simpler and less expensive. The U.S. Department of Energy has determined that to be commercially viable, a hybrid technology vehicle must repay its extra upfront cost in the form of fuel savings within three years of the initial purchase.

Batteries

The goals for a PHEV battery are compact size, high energy, high storage capacity and the ability to support both deep and shallow discharge/charge cycles. A battery small enough to meet the vehicle's form factor and power needs must also be recharged frequently, and over time, the battery loses its ability to take and hold a new charge. Eventually, the battery will need to be replaced. In a car, however, consumers would expect the battery to last the life of the vehicle. Even though a vehicle is safe under normal conditions, a great deal of testing is required to determine battery safety in a crash or fire. As new battery technologies are developed, they will require extensive testing before they are deemed suitable for in-vehicle use.

Research

To address these issues and others, the U.S. Department of Energy is funding research in a variety of technical areas specific to PHEVs. Argonne is participating in all these areas, which include:

• Hardware-in-the-loop analysis
• Modeling & simulation
• Research and development for critical components such as batteries, motors and power electronics
• Component/subsystem testing and validation
• System and interface control development
• Vehicle testing and validation

More

• US-China Electric Vehicle and Battery Workshops
• Driving the Future (pdf)
• Downloadable Dynamometer Database (D3)
• Pulling the Plug on Hybrid Myths
• Just the Basics: Hybrid Electric Vehicles (pdf)
• The Smart Grid

January 2013