Hybrid renewable-hydrogen systems for industrial decarbonization

Hard-to-abate industrial sectors like steel, cement, chemicals, and petroleum refining sectors account for 30% of CO₂ emissions worldwide, thereby challenging climate ambitions. This review paper critically assesses the contribution of hybrid renewable-hydrogen systems and technology architectures integrating renewable energy sources such as solar, wind, hydro, geothermal energy systems, coulpled with hydrogen generation and storage, in facilitating deep decarbonization of these industries. Evidence from flagship projects like Shell's 10 MW Refhyne project and Sweden's H2 Green Steel illustrates emission reductions of 95% using integrated wind-solar-electrolyzer systems. Modelled research indicates that hybrid systems can be cost-competitive with a levelized cost of hydrogen (LCOH) under $2/kg by 2030, rendering green hydrogen economically viable. The review synthesizes more than 10 case studies and 15 techno-economic models with a focus on system architectures, energy flows, electrolyzer utilization, and sectoral applications. Challenges such as high capital intensity, intermittency, and regulatory gaps are also discussed, with strategic suggestions for scaling deployment through hydrogen hubs, AI-driven control systems, and next-generation electrolyzer technologies. Hybrid renewable-hydrogen systems overall, offer a promising solution to minimize emissions, increase industrial resilience, and meet energy transition goals concurrently.