Telefónica has made significant strides in sustainability by introducing an innovative green energy solution for off-grid mobile sites. Initially relying on fossil fuel generators, the company transitioned to hybrid solutions incorporating solar systems and battery banks, reducing carbon footprint by up to 70%. In 2023, Telefónica eliminated the use of fossil fuel generators by introducing hydrogen fuel cells powered by methanol alongside solar energy and battery banks, achieving 100% sustainability. The successful pilot in Kirtorf, Germany, solidified the technology's reliability, showcasing Telefónica's commitment to clean energy. The system's intelligent controller optimizes energy sources, ensuring 100% availability even in areas with unstable or no electrical grid. By producing hydrogen on-site using methanol as a carrier, risks associated with hydrogen storage and transportation are minimized. With plans to expand the technology to Spain, Telefónica aims to further enhance efficiency through detailed sizing and weather-specific adjustments. Overall, the hydrogen-powered solution not only reduces environmental impact but also guarantees constant energy availability in challenging environments, marking a significant step towards a sustainable future.