Hydrogen Production Stabilizes Floating PV-Pumped Hydro Storage

Researchers at the University of Cagliari have demonstrated how integrating hydrogen production can significantly improve the performance of floating photovoltaic-pumped hydro energy storage (FPV-PHES) systems. Published in the Journal of Energy Storage, the study addresses challenges posed by energy curtailment, a situation where renewable energy generation exceeds demand and must be reduced. When faced with high curtailment, FPV-PHES systems without hydrogen production can see their efficiency drop to a mere 24%, driving the cost of electricity to $280 per megawatt-hour. However, the addition of a water electrolyzer to produce hydrogen alters this outlook dramatically. The system then maintains a stable efficiency of 61%, with the levelized cost of electricity falling to $145 per megawatt-hour. This dual-purpose approach not only generates valuable hydrogen, priced at $8.5 per kilogram in the study, but also safeguards the core energy storage function. The research highlights that hydrogen production acts as a crucial buffer, preventing efficiency collapse and economic penalties associated with curtailed renewable energy. The University of Cagliari team plans further investigations into both technical and market-based strategies to further mitigate curtailment risks in these advanced energy storage configurations. This work offers a clear path toward more resilient and cost-effective renewable energy integration.