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Lightweighting Key to Overcoming Barriers to Electrification

By Kelly Vaughn and Bennett Cohen

(Originally published in Greenbiz April 9, 2010)

In a signal that the demand for fuel-efficient and clean vehicles continues to gain momentum, the Obama administration last month convened a meeting of automakers and utility executives to explore how these two historically separate industries will work together to roll out electric vehicles.

And, even though Obama’s ambitious pledge to have one million electric vehicles on the road by 2015 will be supported by $2.4 billion in grants, numerous studies have pointed out multiple barriers to widespread EVs adoption.

The most common are:

  • Limited range
  • Long recharging times
  • High battery costs
  • Insufficient battery manufacturing capacity
  • Current lack of infrastructure and associated cost to build it
  • Integrating electric vehicles with the electric grid
  • Consumers’ upfront costs and payback.

While businesses and policymakers are respectively working to tackle these barriers, Rocky Mountain Institute believes one game-changing solution has received little attention: lightweighting. Shedding some weight could enable the widespread electrification of U.S. personal vehicle fleet—and overcome some of these critical barriers.

How Lightweighting Works

The key to taking significant amount of weight out of a vehicle without making it smaller is to substitute lighter, yet stronger materials such as advanced composites, aluminum, or lightweight steel for heavier materials. Once the platform is lighter, the engine (or battery) can be downsized while maintaining original performance. (Learn more about alternative materials and innovative ways to drive down the cost of production.)

Overall, RMI estimates that average vehicle weight increased 20 percent over the last 20 years—two-thirds of which is from cars getting denser, not bigger. In other words, larger vehicles aren’t causing the automotive pounds to accumulate—it’s bigger engines, thicker steel and heavier parts.


Simply put, every pound removed from the electric vehicle fleet will make electrification easier. Trying to put a battery into a heavy automobile designed to run on an internal combustion engine creates unnecessary challenges. By reducing weight, cars can be designed to run on electricity and reap the multiple benefits of efficiency.

System-Wide Benefits of Lightweighting

The amount of electricity needed to power an electric vehicle is mostly driven by vehicle weight. The heavier the car, the bigger the battery it requires. Bigger batteries cost more (not to mention weigh more), take longer to charge, require a greater level of manufacturing capacity to produce, and increase the demand for new and expensive high voltage charging infrastructure that is a headache for utilities.

Clearly, lightweight EVs can make electrification easier for automakers and utilities. Lightweighting can also increase the value proposition for the consumer by reducing costs and extending electric range.

Smart Policy Can Bring Smart Design

While policymakers most likely won’t sit at the design table with manufacturers, structuring legislation to encourage light and efficient electric vehicles is a smart move.

One recommendation would be to tier tax credits and other incentives by electric vehicle efficiency, rather than battery size.

Current federal tax credits for electric vehicles are equal to $2,500 plus $417 for each additional kilowatt-hour of vehicle battery capacity. While this policy aims to bring down the costs of electric vehicles in proportion to their total cost (batteries are the most expensive component), it provides an incentive for both OEMs and consumers to gravitate toward EVs with larger batteries — the bigger the battery, the bigger the tax credit.

Since batteries are behind the biggest barriers to electrifying transportation, why not structure policy to minimize them? EV tax credits should be based on a metric of vehicle efficiency (for example watt-hours per mile), with more efficient vehicles awarded higher tax credits. Such a system would incentivize OEMs to produce, and consumers to purchase, efficient EVs that require smaller batteries.

Alternately, smart policy could tier tax credits and other incentives by all-electric range. Consumers want longer EV range, not bigger and more expensive batteries. By incentivizing range, OEMs can strive to achieve range targets by the most economic means (decreasing weight or increasing battery size, rather than only increasing battery size).

We Have the Momentum, Now We Need a Breakthrough

As business leaders and policy makers struggle under the weight of the task, they ought to keep in mind an important fact: it’ll be a lot easier to electrify America’s 254 million light-duty vehicles if they weigh half as much.

Now that hybrid-electric vehicles have caught on, and electric vehicles are pushing their way forward, lightweighting has the potential to be the next big breakthrough in the automotive industry. Hopefully we can all look forward to a wave of electric vehicles that are more affordable, efficient and fit.

Kelly Vaughn is a public relations analyst at RMI. Bennett Cohen is special aide to Chief Scientist Amory Lovins.