When we think of critical energy resources, oil, wind, coal, and sunlight are some of the first to come to mind. But one key mineral plays an essential role in keeping the electric grid running, and the U.S. Geological Survey just discovered a vast reserve of it in the eastern United States.
According to a new study published in Springer Nature, the Appalachian region contains an estimated 2.3 million metric tons of economically recoverable lithium concentrated in the Carolinas, Maine, and New Hampshire. That’s enough to replace 328 years of U.S. imports based on last year’s level.
While not a fuel source itself, lithium is the primary component of utility-scale energy storage systems, which stabilize the power grid, balance supply and demand, and support renewable energy integration. Lithium batteries also power consumer electronics, medical devices, electric vehicles, and other essential technologies.
“This research shows that the Appalachians contain enough lithium to help meet the nation’s growing needs—a major contribution to U.S. mineral security, at a time when global lithium demand is rising rapidly,” USGS Director Ned Mamula said in a press release. The agency expects lithium demand to increase more than 48 times by 2040 due to EV production and broader energy storage needs.
Untapped potential
Three decades ago, the U.S. was the world’s top lithium producer, but it has since fallen behind. Regulatory impediments and financing hurdles have stalled domestic projects, shifting production to foreign markets.
Most of the world’s lithium is now mined outside of the U.S., primarily in Australia, China, and Chile. While China isn’t the top producer, it dominates the world’s lithium processing capacity. In 2025, the U.S. relied on imports for more than half its lithium supply, according to the study. This has increased supply chain vulnerability and therefore reinvigorated U.S. efforts to expand domestic lithium production and refining.
USGS geologists assessed the Appalachian region’s lithium reserves using geologic maps, tectonic history, geochemical sampling, geophysical surveys, and records of mineral occurrences. They then ran simulations using a global dataset for lithium pegmatites—large-grained igneous rocks similar to granite—to estimate the number of undiscovered lithium deposits and how much lithium they hold.
The 2.3 million metric tons of lithium oxide they found would be enough to produce 1.6 million grid-scale batteries, or 130 million EVs, according to the USGS.
Getting back in the game
Identifying this lithium reserve is one thing, but tapping into it—and rebuilding a competitive market—is another. Regulatory and financial hurdles still stand in the way, and developing a lithium project can take a decade or more. Only three projects in the U.S. were officially under construction as of August 2025, according to the Federal Reserve Bank of Dallas.
Still, U.S. lithium production is on track to increase, with federal reform helping to clear the way. The past three presidential administrations all worked to expand domestic mining and processing of critical minerals.
The current Trump administration views China’s dominance within the global critical minerals market as a national security threat. In March, the president directed relevant agencies to prioritize U.S. mining and processing of critical minerals by fast-tracking permitting, opening federal lands, and making use of federal financing programs.
The move garnered criticism from environmentalists concerned about undoing green policies for the sake of streamlining critical mineral mining. Others argued that Trump’s anti-renewables agenda undercuts demand for the market he aims to rebuild.
It’s clear that the nation still has a lot to sort through before it can meaningfully tap into the Appalachian lithium reserve. Even with new permitting policies and financing opportunities, it will be a long time before the U.S. can fully develop it into a reliable domestic energy source.
