May 25, 2023 · 57m · catalyst
Four ways to store sunlight
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gold bands on the timeline = statements, start to end. Hover to read, click to jump. CC turns on captions
In this episode of Catalyst, host Shayle Kann and Energy Impact Partners Head of Research Andy Lubershane analyze the challenge of replacing the nation's 47-day fossil energy stockpile, exploring four distinct clean storage pathways: lithium-ion batteries, thermal energy storage, multi-day iron-air batteries, and clean hydrogen.
How this conversation actually went
Every chapter scored 0–10 on four independent dynamics. Hover any point for the reasoning behind the score. Shayle holds 31.7% of the talking time here. How this is scored →
Shayle as informed peer 5.3 Guest teaching 4.1 Guest disagreement 1.1 Shayle pushing back 1.9
speaking balance: gold is Shayle, purple is the guest (3 minute bins)
Sharpest disagreement ▶ 13:00 Andy counters the assumption of low storage needs
Andy pushes back against minimal storage targets, arguing that decarbonized grids will ultimately need strategic reserves much closer to 47 days than a few days.
Hardest push from Shayle ▶ 17:12 Shayle demands clear duration-to-cost explanationShayle interrupts Andy to demand a clearer explanation of the non-intuitive link between storage duration requirements and allowable capital cost.
Biggest teaching moment ▶ 6:50 Andy contextualizes primary energy storage reservesAndy educates listeners and the host on the vast scale of existing fossil stockpiles, breaking down exact figures across natural gas, coal, crude oil, and strategic reserves.
Shayle holds their own ▶ 25:48 Shayle enforces balance-of-system cost rigorShayle leverages deep domain expertise to enforce distinction between cell-level metrics and fully installed turnkey EPC costs for stationary storage.
the scores for every segment, with the reasoning behind each
| Chapter | Topic | Shayle as informed peer | Guest teaching | Guest disagreement | Shayle pushing back | Why |
|---|---|---|---|---|---|---|
| Promotions for Upcoming Climate Tech Events | 0 | 0 | 0 | 0 | Promotional announcements, event sponsorships, and introductory voiceover. There is no substantive technical dialogue in this housekeeping segment. | |
| Shayle Kann Introduces the Four Ways to Store Sunlight | 6 | 5 | 2 | 2 | Shayle and Andy establish the macro baseline of 47 days of fossil fuel storage versus negligible battery capacity today. Shayle probes whether fossil stockpiles exist by strategic design or market consequence, while Andy contextualizes the primary energy numbers. | |
| Category 1: Lithium-Ion Batteries and Their Economic Limits | 7 | 5 | 1 | 3 | The conversation examines lithium-ion battery duration limits and economic cost floors. Shayle interjects with precise industry context regarding total installed turnkey costs versus cell-level costs to clarify Andy's projections. | |
| Midroll Sponsor Break: Bloom Energy and ENGIE Solutions | 6 | 5 | 1 | 2 | Following midroll sponsor reads, Andy breaks down thermal energy storage thermodynamics and past operational failures with molten salts. Shayle connects the discussion to portfolio insights around industrial power-to-heat applications. | |
| Category 3: Multi-Day Iron-Air Batteries and Form Energy | 7 | 4 | 1 | 2 | Discussing Form Energy's iron-air battery, Andy explains capacity resource valuation and low round-trip efficiency trade-offs. Shayle articulates grid modeling findings on how multi-day storage complements short-duration assets during renewable lulls. | |
| Category 4: Clean Hydrogen as Strategic Grid Storage | 6 | 6 | 2 | 3 | Andy walks through the severe power-to-power round-trip efficiency penalties of clean hydrogen while explaining why turbine retrofits and chemical feedstocks create long-term viability. Shayle tests whether gas turbine retrofits justify optimism or skepticism. | |
| The 'Half' Way: Carbon Capture and Storage on Fossil Fuels | 5 | 4 | 1 | 1 | A brief closing exchange frames carbon capture on fossil assets as intermillennial stored sunlight competing directly with long-duration storage technologies. |
Statements from this episode (12)
US currently stores roughly 47 days of primary energy supply in fossil fuels
“We currently store by my rough count, about 47 days on average worth of primary energy supply in the country. So that's it's about nine days of natural gas in storage. It's about 13 days in coal stockpiles. About 10 days in, in crude oil storage. And actually …”
All 2021 US wind and solar equaled only 5 days of primary energy supply
“All of the wind and solar power generated in twenty-twenty-one, if you were to bottle all of that energy up and store it in sort of the same way that we store fossil fuels, it would be only about five days worth of energy supply.”
US grid has only 9 minutes of pumped hydro and seconds of battery storage
“If you were again to compare that to primary energy supply, we have about nine minutes worth of pumped hydro storage, which means we have probably, I don't know, in the seconds level of battery storage capacity today.”
Lubershane: Decarbonized grid storage needs will fall closer to 47 days
“So, you know, between the minutes of energy storage we have today and 47 days, I think we're going to fall probably actually ultimately closer to the 47 days level, ah, than even minutes, hours, or just a few days worth of storage.”
Lubershane: Lithium-ion achieves 80% to 90% AC-to-AC efficiency
“It's actually a remarkably efficient sort of power-to-power energy storage technology. You can get, you know, 80 to 90% AC to AC efficiency levels”
Thermal storage media can store heat at $5/kWh or lower
“The core energy storage components of these materials can be in the ballpark of five dollars per kilowatt hour or lower.”
Lubershane: Lithium-ion fully installed costs are around $300/kWh
“Lithium ion systems, fully installed costs today in the realm of 300 dollars per kilowatt hour. And the cell cost of those systems, which is kind of the closest you can think of as the energy storage, the core energy storage material costs of those systems bei…”
Lubershane: Retiring coal plants can be repowered into thermal storage
“All of these coal-fired power plants that are on track to be retired in the next five to 10 years, maybe a little more than that in some cases. And as they're retired, they're sitting there, and they've got, you know, everything you need, basically, to repower…”
Lubershane: Form Energy's 100-hour battery will cost under a tenth of lithium-ion
“Form is on track to achieve a total installed cost. We're not talking about the cost of the materials here, but a total installed cost for a approximately a hundred hour battery system, which is basically a four day battery system that is in the ballpark of a …”
Lubershane: The grid will require three distinct storage tranches and technologies
“I think we're going to end up with sort of three tranches of storage in the grid, which are going to be filled by at least three different technology categories. The first is those short duration, you know, peak of the peak applications that lithium ion is, is…”
Lubershane: Hydrogen roundtrip power-to-power efficiency tops out at roughly 35%
“At the end of the day the round trip power to power efficiency for hydrogen, just as a storage medium, is probably gonna be in the range of, like, 20 to, at most, maybe 35%.”
Lubershane: Economically viable CCS will compete directly with grid energy storage
“To the extent CCS becomes, you know, proven and economically viable, I think it serves as a competitive force on, you know, any of these opportunities for grid storage and for energy storage over time, because it, you It's probably the next best alternative.”