Immersion cooling submerges battery cells and modules directly in a non-conductive dielectric fluid — delivering unmatched safety, longer life, and denser deployments than air or cold-plate cooling.
The entire battery module — cells, busbars, interconnects — sits in a dielectric fluid. Heat is absorbed directly from every surface; oxygen is excluded at the cell level.
Cells are fully submerged in a non-boiling dielectric fluid (synthetic ester or PAO-based). A heat exchanger circulates the fluid to remove thermal energy. Simple, reliable, with biodegradable options available.
Cells sit in a low-boiling fluorocarbon that vaporizes at the cell surface and condenses on external coils. Delivers the flattest temperature distribution of any BESS cooling method — ideal for high C-rate applications.
The fluid blocks oxygen at the cell surface and absorbs thermal-runaway energy. In UL 9540A testing, adjacent cells stayed below 50°C while a failing cell reached 500°C — zero propagation.
BESS is moving into cities, basements, substations, and commercial buildings — where electricity has its highest value but fire perception has blocked deployment.
~100 active BESS moratoriums in New York alone. The 2025 Moss Landing fire in California. Batteries in dense urban spaces carry unacceptable fire risk with air or cold-plate cooling.
Immersion cooling structurally eliminates thermal-runaway propagation. It's not a suppression add-on — it's inherent to the design. The dielectric fluid is present from cell to module to rack, creating a continuous fire barrier.
Longer cycle life (uniform temperature = slower aging), no derating at high charge/discharge rates, 30–50% smaller footprint, and access to building types previously off-limits to battery storage.
Three cooling architectures compete in BESS. Only immersion eliminates thermal-runaway propagation structurally.
From AI data centers to remote mines — any space where a battery fire is not an option.
In-rack batteries for AI load buffering (millisecond GPU swings). UPS companion systems. Zero-fire-risk deployments in occupied buildings.
Enclosed manufacturing spaces, mines, oil & gas platforms. High-C-rate load leveling where fire exposure to production is unacceptable.
Urban substations, frequency regulation, renewable firming. The largest immersion market segment at 32.5% of total.
High-power fast-charging stations with immersion-cooled buffer batteries. Compact, safe, no derating during peak demand.
Island-mode storage where a battery fire destroys the only power source. Military, campus, and remote community deployments.
5G/6G base stations in weather-exposed cabinets. Longer life in extreme temperatures, no maintenance access needed.
Four analyst estimates span a wide range — but all agree on one thing: immersion cooling is entering exponential growth.
The directional picture is consistent across all four estimates: high-teens CAGR, still a small slice of the $77B stationary BESS market, with data centers and grid storage as the leading applications. Immersion cooling is at the same inflection point as lithium-ion batteries were in the early 2010s — proven technology, scaling rapidly, and about to become the default for safety-critical deployments.
The immersion cooling ecosystem spans startups and incumbents — all racing to standardize and scale.
Fortis Series — first commercial immersion-cooled BESS line for data centers. LiquidShield™ fluid + HazGuard™ gas mitigation. UL 9540A no-propagation results. Available Q4 2026.
Pioneer of dielectric-fluid immersion with HPC heritage. Listed among immersion storage market leaders. Scaling from server racks to battery storage.
Two-phase immersion-cooling leader with LiquidStack platform. Strong in HPC, expanding into BESS for high-performance energy storage.
Shell (certified battery dielectric fluid), CATL (5 MWh EnerD line), and UPS majors (Schneider, Vertiv, Eaton) transitioning data-center battery lines toward lithium and higher-safety chemistries.