The Power of Persistence

“Infantry wins battles. Logistics wins wars.”

This quote, attributed to U.S. Army General John Pershing in the context of World War I expeditionary operations, is equally applicable today as we move further into the era of autonomous undersea systems. From the age of sail to the nuclear age, maritime power has been underpinned by how far and how long forces could operate forward, and while logistics has traditionally meant sustaining crews and platforms with fuel, food, and materiel, the logistics burden of autonomous underwater operations increasingly centers on one fundamental requirement: energy. It is energy that powers every onboard system – propulsion, navigation, communication, and autonomy – and ultimately enables the mission-critical endurance necessary to maintain a persistent subsea presence.

For years, the dominant underwater power paradigm has been stored energy. With their high energy density, scalability, and mature manufacturing base, lithium ion (Li-ion) batteries have been the standard for underwater systems for defense and commercial customers alike. But Li-ion’s long-standing dominance could be giving way as onboard energy production, in the form of hydrogen fuel cells, is steadily gaining traction.

While a relatively new innovation for autonomous underwater operations, hydrogen fuel cells have been employed by crewed submarines for years