Historical and future trends in water electrolysis investment cost and technical performance: A literature review

This is the authors' abstract. We don't add key points for this paper.

This literature review evaluates four main water electrolysis technologies in terms of their historical, current and projected technical and economic performance: alkaline (AEL), proton exchange membrane (PEMEL), solid oxide (SOEL), and anion exchange membrane electrolysis (AEMEL). A structured methodology was employed to harmonize and compare data from peer-reviewed studies, organizational reports, manufacturer specifications, and expert knowledge. Five key performance indicators were evaluated: capital expenditure, specific energy consumption, efficiency, degradation rate, and lifetime. The published estimates and projections indicate declining investment costs, improved energy efficiency, and increased durability across all technologies. Within the harmonized dataset, AEL generally exhibits the lowest reported specific investment costs, while published projections indicate greater future cost reductions and performance improvements for PEMEL, SOEL and AEMEL. The review further highlights considerable variability among published values, emphasizing the need for greater transparency and harmonization to improve the comparability and reliability of techno-economic assessments.