Plug-in electric vehicles (PEVs) have the potential to dramatically drive down consumption of carbon-based fuels and reduce greenhouse gas emissions, but the relatively high price of these vehicles—due in large part to the cost of batteries—has presented a major impediment to widespread market penetration. Researchers at the Energy Department’s National Renewable Energy Laboratory (NREL) are playing a crucial role in identifying battery second use (B2U) strategies capable of offsetting vehicle expenses while improving utility grid stability.
 Lithium-ion (Li-ion) batteries, the energy storage technology of choice for PEVs, are typically the most expensive components in those vehicles, and their disposal presents environmental challenges. Second-use options support a broad spectrum of sustainable energy strategies, as they increase the potential for widespread PEV adoption by eliminating end-of-life automotive service costs, in addition to helping utilities support peak electricity demands while building a cleaner, more flexible electricity grid. NREL research confirms that after being used to power a car, a Li-ion battery retains approximately 70% of its initial capacity—making its reuse a valuable energy storage option for electric utilities, before battery materials are recycled.