Misguided proposal for electric car batteries could actually increase California emissions

California has done more than any other state to facilitate the widespread adoption of electric vehicles, and it recently announced new measures to do so again. This time, however, the state is pursuing an EV policy whose tradeoffs have not yet been sufficiently evaluated.

A recent proposal from the California Air Resources Board (CARB), the state’s clean air watchdog, would require EVs built in 2026 and beyond to have batteries that maintain 80% of their power for at least 15 years. This “durability requirement” is intended to promote the resale of used EVs by assuring purchasers that the battery still has enough remaining life to run the car.

Current federal rules require EV batteries to last eight years or 100,000 miles. Manufacturers design batteries to meet that standard, and most will replace batteries that fall below 70% capacity.

Promoting the broad use of EVs, including used ones, supports California’s goal of reducing greenhouse gas emissions. But potential undesirable outcomes of this proposal includes batteries being replaced before the end of their useful life; adding weight and decreasing vehicle efficiency; and an increased cost of batteries that has potential to slow market adoption of EVs.

The proposal could also overwhelm the nascent EV battery recycling industry, which is racing to prepare for the nearly 16 billion pounds of lithium-ion EV batteries (approximately 403 million batteries) expected to reach end of life by 2040.

This mandate will influence battery-related environmental emissions in ways that haven’t been analyzed or fully understood. All stages of the battery life cycle — from raw materials extraction through manufacturing, use, charging, secondary use outside the EV and eventual recycling — have emissions properties that must be considered and weighed when creating public policy.

A better direction would be to focus on maximizing value and minimizing emissions in every stage of the EV battery life cycle. Leaders in California and elsewhere should drive policy toward creating a “circular economy” for EV batteries, like what has already been achieved for lead-acid batteries. This approach is embodied in a set of principles developed by the University of Michigan Center for Sustainable Systems.

At their core, this approach is about informing battery technology development through a sustainability lens as the EV market continues to grow. With a data-driven framework, the green principles are intended to educate material suppliers, battery and vehicle manufacturers, national labs, consumers and recyclers so they can make informed decisions on sustainable battery management practices.

As the world moves steadily toward adopting EVs, policy mandates, such as those being advanced by CARB, must be backed by data, science, comprehensive analysis of the trade-offs involved in battery technology, production, use and multi-stakeholder review prior to enactment.

Prioritizing the single outcome of sufficient battery life in used EVs over sound, science-based public policy undermines progress toward establishing a true circular economy for batteries that minimizes full life cycle environmental and emissions impacts.

The main goal of adopting EVs is to reduce greenhouse gas emissions. That should be the starting point of any policy discussion.