A Cornell-led collaboration has developed a groundbreaking method to produce carbon-free green hydrogen through solar-powered electrolysis of seawater, while simultaneously generating potable water. The team's hybrid solar distillation-water electrolysis (HSD-WE) device can currently produce 200 milliliters of hydrogen per hour with 12.6% energy efficiency directly from seawater under natural sunlight. The technology aims to reduce the cost of green hydrogen production to $1 per kilogram within 15 years, a significant step towards achieving net-zero emissions by 2050. Led by Lenan Zhang, the team leveraged the abundant and free resources of solar power and seawater to address the high cost associated with traditional green hydrogen production, which relies on deionized water. By utilizing waste heat from photovoltaics to warm seawater until it evaporates, the device achieves high evaporation efficiency of over 90% through a capillary wick, simultaneously producing potable water. The researchers foresee potential applications of the technology in solar farms to enhance PV panel efficiency and lifespan. With the support of the National Science Foundation, this innovative approach not only tackles energy and water scarcity challenges but also demonstrates promising market potential for widespread adoption.