

E101: Reinventing Grid Storage with XL Batteries
Sep 4, 2025
40:02
For the next few episodes, we’re digging into the wild world of energy and the aging global electricity grid. This week, we start where reliability begins: utility-scale storage. The grid we have was built for one-way power plants; the grid we need has to juggle rooftop solar at noon, heat waves at 6 p.m., EVs, and data centers galore.
My guest is Tom Sisto, founder & CEO of XL Batteries. His team is commercializing a pH-neutral, aqueous organic flow battery — a non-flammable, salt-water system using carbon-based molecules instead of vanadium. Think: safer, long-life storage you can scale for hours to days, without sulfuric acid or scarce metals.
We get into:
- Why storage is the “time machine” the grid needs (match generation to demand, cut curtailment)
- Flow batteries 101: engine vs. tank, independent power and duration, and why that matters for utilities
- XL’s chemistry: organic charge carriers in neutral saltwater (no vanadium, no acid), designed for long life
- Cost and safety vs. lithium — and why duration + cycle life drive utility economics
- Real-world progress: containerized field unit, EPRI duty-cycle testing, and an industrial pilot at Stolthaven Terminals
- Retrofit potential: turning existing petrochemical tanks into energy storage tanks
- Storage-as-transmission: placing batteries on both sides of a bottleneck to double effective flow
- Reliability + resilience: PSPS/wildfire shutoffs, hurricane backup, and data-center load growth
- Where decentralization fits, and how industrial customers can de-risk adoption on the way to utility scale
Links & resources:
- XL Batteries — https://xlbatteries.com/
- Everybody in the Pool: all episodes & newsletter — https://www.everybodyinthepool.com/
- Become a paid subscriber for an ad-free feed (and my eternal gratitude) — https://plus.acast.com/s/everybody-in-the-pool
Call to action & what’s next:
- Send thoughts & voice memos: in@everybodyinthepool.com — where do you see storage unlocking reliability?
- If you liked this one, share it with a grid geek friend.
Smart Grid Series lineup:
- E101 (this episode): Safe, long-duration flow batteries with XL Batteries
- E102 (next): Grid “airbags” — synthetic inertia & fast frequency control with Wärtsilä
- E103 (after that): A rechargeable zinc sponge anode that solves dendrites — Enzinc
Hosted on Acast. See acast.com/privacy for more information.