Hydrogen as an alternative fuel: A comprehensive review of challenges and opportunities in production, storage, and transportation

Abstract

The rapid growth of the global population and industrial activities has significantly increased greenhouse gases (GHGs) emissions, with projections indicating a temperature rise of 3–6 °C by 2050. Urgent action is needed to limit global warming to 1.5 °C above pre-industrial levels. Hydrogen, with its high energy density and compatibility with renewable energy systems, presents a promising clean energy solution to mitigate GHGs emissions. Yet, its widespread adoption faces challenges such as high production costs, limited infrastructure, and an underdeveloped value chain. At present, approximately 96% of global hydrogen production relies on fossil fuels, contributing to substantial emissions, while only 4% comes from water electrolysis. Green hydrogen, produced via electrolysis with 55–80% efficiency, remains expensive at $2.28–7.39/kg, compared to grey hydrogen at $0.67–1.31/kg, which generates 8.5 kg CO₂ per kg of hydrogen production. Hydrogen's low density poses challenges for storage, while transportation risks and insufficient infrastructure create further obstacles. The lack of global standards and investment uncertainties further impede the development of a comprehensive hydrogen economy. This review evaluates hydrogen's potential as a sustainable energy carrier, providing insights into advancements and ongoing challenges in production, storage, and transportation. Key findings highlight the necessity of coordinated efforts to enhance storage technologies, lower production costs, and establish supportive policies, highlighting hydrogen's critical role in achieving a sustainable energy transition.