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 policymakers 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 an analyst with RMI's Communications Department, where she focuses on communications strategy and initiative development. Bennett Cohen is a special aide to RMI Chief Scientist Amory Lovins and currently leads the organization’s oil solutions initiative, an effort aimed at collaboration among the many organizations working to end U.S. oil dependence.