On July 14, 2021, the U.S. Department of Energy (DOE) announced a new goal under the Energy Earthshot Initiative’s (Energy Earthshots): “Long Duration Storage Shot.” The Energy Earthshots program focuses on scientific breakthroughs that can lead to more abundant, affordable, and reliable clean energy solutions within this decade as the United States aims to achieve net-zero carbon goals by 2050. The second target within Energy Earthshots aims to accelerate innovation in long-term storage of clean electricity. Long duration energy storage, defined by DOE as systems that can store more than ten hours of energy at once, would facilitate the capture and storage of energy for later use when energy generation is unavailable or lower than demand. Scenarios provided by DOE include solar-generated power that could be used at night or nuclear energy generated during times of low demand to be used when demand increases. The Long Duration Storage Shot will consider all types of technology, including electrochemical, mechanical, thermal, chemical carriers, or combinations of these technologies.