Episode 150 | Durable Durations | PowerGen International ’22 (Live)
At long last, a panel in person! It had been three years since I last hosted a non-virtual panel, and this one did not disappoint.
For the topic, “Options for Long Duration Energy Storage," I had three amazing guests:
First off, what is “long duration?” Several sites say anything 10 hours or greater fits the definition, though some may say longer than 6 hours. Typical lithium-ion battery systems on the grid are good for 2-4 hours of storage.
Erik, our first presenter, is developing two pumped hydro projects in the northwest U.S. He says anything less than six hours has “low capacity value” for the utilities now forced top reckon with West Coast energy mandates.
“By 2019/2020, the whole West Coast was aligned in 100% clean mandates,” he says, “and all the various utilities are focused on their integrated resource planning processes on how they’re gonna deal with that.”
Hugh’s technology, an iron flow battery, is currently good for about 12 hours. The key to their technology is an electrolyte comprised of iron in saltwater, which comes out of solution during a charge cycle. Hugh says ESS’s innovation was making the process “inert,” and therefore capable of a nearly endless number of cycles.
“A few years down the road, if I wanted to expand the energy capacity, all I’m doing is adding liquid,” he says.
Doug’s role is to determine the best storage solution for a given use case. He says there are over 600 ways to store energy. His group has identified 230 technologies and ranks them for a given job based on 12 characteristics (see Slide).
“Long duration storage as far as I’m concerned means that you’re going to be able to put power for months,” he says, “not days, not hours.”
One of the concerns from both panelists and attendees was the need to insure these newer technologies. ESS spent nearly two years developing a warranty for their batteries. Doug says of the 230 technologies they’ve evaluated, ⅓ are currently not insurable.
Supply chains were another issue. Hugh says 85% of components for ESS batteries can be sourced in the United States. They have “strategically stocked” other components (i.e. electronics) sourced overseas.
Erik says part of their appeal from lawmakers in particular is building storage that does not rely on the same materials needed for electric vehicle infrastructure (i.e. lithium ion batteries).
So, what battery is best?
“There’s ‘horses for courses,’ as my dad would say,” says Hugh. “We don’t think there’s going to be any one silver bullet that solves all the spectrum of needs. There’s going to be a different mix of battery storages that make up the whole spectrum here.”
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