It’s depressing that lithium batteries get almost all of the focus in the energy storage industry. Lithium batteries have a number of advantages, including high energy density, good longevity, declining costs and established integration with electronics, vehicles and stationary energy storage. Although ideal for residential and commercial storage applications, 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 have the potential to meet these utility storage application needs. Flow batteries use two tanks of liquid electrolyte, separated by a special membrane, that 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. The power output of a flow battery depends on the size of the anode and cathode electrodes in the battery cell.

Since their storage capacity is limited mostly by the size of the electrolyte tanks, flow batteries are great for grid-scale storage. They are also finding applications when sited alongside PV systems. Since the battery can absorb power in excess of what the grid or inverter can handle, inverters can be smaller — resulting in lower equipment costs and greater efficiency.

I heard about new flow battery technology from my friends at NexTracker. I was initially hesitant to learn about flow batteries – one could say I’m in a lithium rut waiting for the commercialization of dual lithium crystalline reactor technology for interstellar travel. But when I understood the real-world benefits of Avalon’s batteries when integrated with utility-scale tracker installations, I was convinced.

So on this week’s show we’re going with the flow. Our guest is Matt Harper, Co-Founder and Chief Product Officer of Avalon. I hope you tune in to this week’s Energy Show as Matt explains the technology behind flow batteries, practical applications, availability of electrolytes, and Matt’s view of how flow batteries have the potential to meet our long duration energy storage needs.