Green hydrogen in the renewable energy transition exploiting: A systematic review

• Green hydrogen helps reduce the environmental damage caused by conventional fossil fuels. • The obstacles that must be addressed for green hydrogen to emerge as a practical and competitive replacement for traditional energy source. • The strategic pathway for advancing and scaling up green hydrogen technology in the coming years. • The promising advantages of green hydrogen in building a sustainable future and enhancing the integration of renewable energy into the global energy system. Green hydrogen, generated exploiting sustainable energy supplies, is materializing as a decisive component in the worldwide progression to eco-friendly energy systems. This review examines recent developments in green hydrogen production, focusing on key electrolysis technologies such as proton exchange membrane (PEM), basic and solid oxide methodologies, along with biological and thermochemistry strategies. Although the promise for clean hydrogen is substantial, several hurdles remain—particularly high production costs, significant energy demands, and difficulties related to storage and distribution. However, the sector is witnessing increased momentum, fuelled by international investments and supportive policy frameworks that are expected to reduce factory overheads to not more than $2 per kilogram no later than 2030. Nations like India, Japan, Australia in addition Germany are piloting efforts with national strategies aimed at scaling up electrolyzer deployment and incorporating sustainable hydrogen in the direction of industries including transit, energy output and manufacturing. Technological innovations in electrolyzer efficiency, advanced materials, and seamless integration with renewable power sources are projected to augment the commercial proficiency and practicability of green hydrogen. This review underscores the importance of coordinated policy initiatives, ongoing research and development (R&D), and strategic investments to accelerate the adoption of green hydrogen as a pivotal solution for reducing carbon emissions and enhancing energy autonomy and supply reliability. By aligning technological innovation with supportive policy frameworks and financial mechanisms, stakeholders can overcome current barriers in infrastructure, production scalability, and cost competitiveness. Furthermore, fostering international collaboration, incentivizing public-private partnerships, and establishing standardized certification and regulatory pathways will be crucial for driving widespread deployment and ensuring the long-term sustainability of green hydrogen systems.