AI Summary
5 min readAnduril’s Dr. Andrew Nuss explains that moving a vehicle one nautical mile through water takes about a thousand times more energy than moving it through air. That single fact shapes nearly every energy decision in maritime defense: how batteries are packaged, whether diesel or fuel cells make sense, and why autonomy is finally exposing energy as the binding constraint on undersea missions.
Why maritime defense is a different energy problem
The maritime domain is uniquely hostile. Saltwater corrodes everything. Pressure at depth tries to crush any system. And unlike ground vehicles, an undersea vehicle must carry all its energy from the moment it leaves the pier—there is no refueling infrastructure at sea. Commercial off-the-shelf lithium-ion batteries cannot simply be dropped into an underwater vehicle; they need to be either sealed inside a pressure vessel (which fights off depth) or potted in epoxy as a pressure-tolerant system. Both approaches are capital-intensive and require lengthy certification.
Continue reading the full summary in the app — free to try.
Read Full Summary →Free • No credit card required
Never miss an episode of Catalyst with Shayle Kann
Get every new episode summarized in your inbox — free, ~5 minutes to read.
No spam. Unsubscribe anytime.
What you'll learn
- 1 (00:02) **Introduction: Why defense maritime energy matters** - Shayle Kann frames the episode around two axes: what's unique about maritime vs. other transportation, and what's unique about defense vs. commercial energy needs.
- 2 (03:25) **The harsh reality of undersea energy systems** - Commercial off-the-shelf lithium batteries fail quickly at depth; packaging and certification are the core challenges.
- 3 (05:55) **Propulsion energy dominates, but autonomy changes the ratio** - Moving one nautical mile underwater takes ~1,000x more energy than in air, yet new robotic missions are now stressing the energy system.
- 4 (10:44) **Three energy architectures for undersea vehicles** - Buoyancy engines, battery systems, and diesel-electric/fuel cells each have distinct trade-offs.
- 5 (13:03) **Why lithium-ion is the default (and the problem)** - The undersea market is a tiny fraction of consumer battery demand, forcing it to be a "fast follower."
- 6 (14:30) **What defense customers actually need: persistence and flexibility** - Unlike commercial missions, defense requires long-range stealth transit, loitering on station, and then extraction—all without being detected.
- 7 (16:26) **The operational penalty of diesel-electric systems** - Surfacing to recharge introduces hazards and consumes energy, making it far less attractive than it first appears.
+ Full timestamped outline available in the app
Show Notes
Dual-use technologies and the rise of defense tech are having a moment. But how does the defense sector approach innovations in energy that may be necessary to optimize its fleets?
To help answer that question, Shayle turns to the maritime sector to explore how advanced batteries, nuclear propulsion, and autonomous capabilities are shaping the future of defense.
Unlike conventional EVs, maritime vehicles and drones must compete with the challenges presented by the sea in order to complete surveillance and reconnaissance-related missions, as well as direct attacks. Saltwater corrodes hardware, and vehicles at great depths must withstand enormous pressure; to say nothing of the fact that moving through water requires nearly 1,000 times more energy than through air.
To learn how the sector navigates these obstacles, Shayle sits down with Andrew Nuss, the head of growth and strategy in the maritime division at the defense technology company Anduril. They unpack topics including:
- The complicated physics influencing maritime drone design and energy usage
- How lithium-ion cells fare in deep-sea deployment
- Why extreme reliability and long-range capabilities drive the military’s energy requirements compared to commercial shipping
- How surface or subsea recharging depots could reshape vehicle design
- Why both commercial and defense sectors are revisiting nuclear propulsion as a viable option for high-speed, zero-emission surface vessels
Catalyst: The rise of metal fuels
- Catalyst: GM’s big new battery tech push
- Catalyst: Decarbonizing the high seas
- Open Circuit: A five-alarm fire for the grid?
- Latitude Media: Is adaptation ready for growth money?
Credits: Hosted by Shayle Kann. Produced and edited by Max Savage Levenson. Original music and engineering by Sean Marquand. Stephen Lacey is our executive editor.
Catalyst is brought to you by EnergyHub. Peak season puts every grid to the test — and the utilities that pass are the ones that built flexible capacity before they needed it. EnergyHub works with more than 170 utilities to coordinate 2.5 million devices and 3.4 gigawatts of dispatchable flexibility through a single platform designed to perform when it counts most. See what that looks like at https://www.energyhub.com/
Catalyst is brought to you by Bloom Energy. Bloom
More from this podcast
Catalyst with Shayle Kann →