Recent breakthroughs suggest that hydrogen reservoirs are buried in numerous regions globally, including at least 30 U.S. states. This discovery offers a potential solution to accelerate the global energy transition away from fossil fuels. Geologists, led by Chris Ballentine from the University of Oxford, have unveiled key insights into the formation and location of these hydrogen accumulations within Earth's crust. Ballentine's new research outlines that Earth's crust has generated sufficient hydrogen over the past billion years to fulfill current energy needs for 170,000 years. However, the accessibility and profitability of extracting this hydrogen remain uncertain. The study, published in Nature Reviews Earth and Environment, identifies the geological conditions necessary for the formation and retention of natural hydrogen gas underground, emphasizing the importance of identifying suitable reservoir rocks and seals. Exploration companies like Koloma, Hy-Terra, and Snowfox, backed by notable entities such as Bill Gates' Breakthrough Energy fund and BP, are actively scouting for potential hydrogen sources. Key geological contexts, such as ophiolite complexes, igneous provinces, and Archaean greenstone belts, are highlighted as promising regions for exploration. While hydrogen is crucial for industrial applications like methanol and ammonia production, its potential as a clean energy source for vehicles and power plants is significant. Current hydrogen production heavily relies on hydrocarbons, resulting in substantial carbon emissions. The presence of natural hydrogen reservoirs offers a sustainable alternative with a considerably smaller carbon footprint. The research not only serves as a fundamental guide for hydrogen exploration but also underscores the vital role of clean hydrogen in advancing energy sustainability. By leveraging Earth's rich hydrogen resources, the path towards a greener and more efficient energy landscape becomes increasingly tangible.