Given the significant reliance on data centers for the functioning of various industries and their growing contribution to emissions and energy usage, evaluating sustainable power solutions becomes increasingly important. This is particularly evident amid rising data center energy consumption, driven by the rapid expansion of AI-driven workloads and cloud computing.
Until recently, most initiatives relied on voluntary commitments by industry actors, leading to variations in definitions, targets, and transparency levels. However, this landscape has evolved with the introduction of binding regulatory frameworks within the European Union. The revised Energy Efficiency Directive establishes mandatory reporting requirements, while the European Commission is preparing a Data Centre Energy Efficiency Package to introduce a rating scheme and enable performance benchmarking.
In this context, Li-ion battery energy storage systems and hydrogen-powered fuel cells represent key technologies for data center backup power. While Li-ion technologies benefit from cost reductions and industrial scaling, fuel cells offer emission-free power at a megawatt scale. However, fuel cells remain constrained by high costs and the limited availability of low-carbon hydrogen.
This paper assesses the feasibility of Li-ion batteries and hydrogen fuel cells based on a qualitative comparative analysis across five key dimensions: technology characteristics and performance, industrialization and deployment readiness, cost dynamics, environmental impact, and social acceptance.