Aluminum Use in EVs Will Reduce Battery Requirements, and Overall Vehicle Costs, for Plug-Ins and Hybrids, Association Study Confirms

Opting for high-strength, low-weight aluminum over heavier steel structures for plug-in electric and hybrid vehicles can cut overall vehicle price by reducing the battery energy requirements and the associated costs, according to a new study released at the Center for Automotive Research's Business of Plugging In conference. The study was jointly conducted by the Aluminum Association and Ricardo, a leading technical research and strategic consultancy to the world's automotive, transport, and energy industries.

Michael Bull, Director of Automotive Technology for Novelis, represented the Aluminum Association at the conference and participated in a panel discussion on future automotive changes associated with electric vehicles.

“As automakers gear up for a new generation of plug-in electric vehicles, the high cost of battery power remains a barrier,” said Bull. “What this new report shows is that by upgrading from traditional steel to an advanced aluminum body structure, the vehicle's stored energy requirements can be cut by about 10 percent, which could save up to $3,000 per vehicle, since less power and energy is required to move the lighter vehicle.”

“Plug-in and hybrid electric cars contain precious little, and quite expensive, 'fuel' in the form of batteries,” added Bull. “Therefore, every effort must be made to utilize this stored energy to the highest possible efficiency. The solution lies in lowering the vehicle's weight with aluminum as part of a holistic approach to also include advanced powertrains and batteries, enhanced thermal management, improved aerodynamics, and reduced rolling resistance.”

The electric vehicle study found that the driving range of the vehicles could be improved proportionately to the mass saved, i.e., reduce the mass of the vehicle 20 percent, go 20 percent farther. One example vehicle had its range extended from 80 to 97 miles.

The study also examined the role of vehicle mass on regenerative braking - specifically the question of whether strong regenerative braking might lessen the impact of weight reduction. This turns out not to be the case. All vehicles studied could recoup about 65 percent of the energy associated with moving the vehicle. But the energy balance for each vehicle changes. As the vehicle gets lighter, less energy is required to move it, while the aerodynamic losses remain constant. For the lightest vehicle, the aerodynamic losses are higher than the energy to accelerate the vehicle.

Real world designs support the fact that lightweight structures are a significant enabler for these vehicle types. Examples include Tesla Motors' Roadster, Fisker Automotive's luxury vehicle, and Bright Automotive's van. All use lightweight aluminum platforms.

“Many of the current hybrid vehicles are progressively adding lower-weight components to improve the overall vehicle performance,” said Bull. “When it comes to making electric vehicles more affordable and efficient, aluminum is proven to get you there with no compromises."

For a more detailed summary of the Ricardo study, click here. For further information about the study, contact Kristin Tyll at (248) 824-8200 or ktyll@stratacomm.net.

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