Can Flow Batteries compete with Lithium-ion for utility scale energy storage?
- Sep 20, 2019 5:09 pm GMT
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Flow batteries use two tanks of liquid electrolyte, separated by a special membrane, which flows between the anode and the cathode within the battery cell. Energy is stored in this liquid electrolyte instead of as part of the electrode material in conventional batteries. The energy storage capacity of a flow battery is related to the amount of liquid electrolyte — bigger tanks provide greater storage capacity.
Utility scale storage batteries require long term and high capacity energy storage — which are not necessarily the characteristics of the old style lead-acid batteries that have been in use since 1859, as a cranking battery in our cars, without any modifications, probably due to overwhelming cost vs. benefits.
Lithium-ion, which utilizes the same basic technology in about nine or more similar variants, suitable for different implementations, is using exotic materials for achieving higher storage capacity with lower weight, much higher energy density when compared with lead-acid. The engineering trade-off here is a substantially higher cost, which make those suitable for aviation and other transportation vs. ground applications.
In engineering we are always looking for the lowest cost solution that meets or exceeds the Tech Specs. Lithium ion chemistries are not great for long term and high capacity energy storage -which are the characteristics that many utility storage installations require. Flow batteries, with external large tanks of liquid electrolyte, have the potential of meeting utility scale long duration energy storage needs.