Electrolyte tank costs are an overlooked factor in flow battery economics

The economic viability of flow battery systems has garnered substantial attention in recent years, but technoeconomic models often overlook the costs associated with electrolyte tanks. This work challenges the commonly assumed insignificance of electrolyte tank costs in flow battery research and demonstrates their substantial impact on overall system economics. Using prices quoted by globally distributed tank manufacturers, it is shown that tank costs in most published technoeconomic models are severely underestimated, if not entirely neglected. Back-of-the-envelope calculations show that electrolyte tanks may constitute up to 40% of the energy component (tank plus electrolyte) costs in MWh-scale flow battery systems. Standardization of flow battery components and the development of high-voltage chemistries are highlighted as paths towards decreasing costs and achieving greater market penetration.