H2 EnerFLOW Vanadium Flow Battery ESS

H2, Inc. is a South Korean developer of vanadium redox flow batteries and the energy storage systems built on them. It reports the first commercial vanadium flow battery deployment in South Korea and targets generation companies and grid operators that need safe, scalable, long-duration storage to integrate more renewable energy.

The EnerFLOW series uses proprietary technologies named HYPERBOOST, FUSIONCELL, FLEXMODULE and HYPERDENSITY. EnerFLOW 510 is a stackable 45 kW / 200 kWh module scalable to hundreds of MWh, while EnerFLOW 640 is a three-block system of 500 kW / 3,057 kWh. Both offer 4 to 12-hour duration, 100% depth of discharge, an integrated BMS and Modbus TCP/IP interface, for uses such as resource adequacy and transmission and distribution deferral.

• EnerFLOW 510: stackable 45 kW / 200 kWh module for minimum footprint.
• EnerFLOW 640: three-block 500 kW / 3,057 kWh system for utility projects.
• Long duration: 4 to 12 hours with 100% depth of discharge.
• Proprietary stack: high power-density cell stack and electrode technology.
• Integrated BMS: Modbus TCP/IP interface for plant control systems.
• Certifications: UL-certified flow battery stack and Korean NEP product certification.

Power generation companies in Vietnam could pair solar or wind farms with multi-hour flow storage to reduce curtailment. Industrial parks could install non-flammable storage near factories for peak shifting. Grid operators could defer substation upgrades in congested areas.

The aqueous electrolyte carries no fire risk, allowing installation in industrial complexes. Power and energy are decoupled, so duration can be extended by adding electrolyte. The systems are rated for more than 20,000 cycles and a design life above 30 years with 100% depth of discharge, giving a competitive levelised cost for long-duration use.

Grids with rising solar and wind shares need storage lasting well beyond four hours, and fire safety rules are tightening for lithium-ion systems in industrial zones. Korea, Japan and Southeast Asian markets are opening tenders where non-lithium, long-duration storage can compete.

South Korean company focused on vanadium flow batteries. Its stack (model 5266) received UL certification and its H2G flow battery gained Korean NEP certification in 2022. Signed a 2025 Deep Tech Challenge Project agreement with the Korean government and exhibited at InterBattery Europe 2025.