HyWatts, a California-based green hydrogen startup, has introduced a new approach to powering electric vehicle charging stations in off-grid locations. The company’s technology aims to address reliability challenges in areas without traditional grid access by integrating hydrogen production and storage with renewable energy sources.
The company’s core innovation is a “Power-Plant-in-a-Box” system that operates as a self-contained unit capable of generating electricity directly from solar power during daylight hours while simultaneously converting excess solar energy into hydrogen for storage. This dual functionality allows hydrogen to serve as a long-duration energy storage medium, with the ability to maintain charge far longer than conventional lithium-ion batteries. The system includes a proprietary “Reversible Fuel Cell” that combines electrolyzer and fuel cell operations within a single integrated device.
HyWatts’s approach uses a high-temperature proton exchange membrane operating between 120°C and 180°C, significantly higher than traditional PEM systems that operate at 60°C to 80°C. This higher temperature range eliminates the need for complex liquid cooling systems, reduces water treatment requirements, and allows the system to use steam as a demineralized water source. The heat generated during the electrolyzer process is recycled as pressurized steam and reapplied to improve overall efficiency. The company has developed a phosphoric acid-doped membrane as an alternative to conventional membranes, addressing challenges related to acid loss during operation.
The green hydrogen sector in the United States faces headwinds following policy changes that disrupted federal hydrogen hub programs. Despite this challenging environment, other innovators continue pursuing commercial opportunities. Texas-based Talus Ag is developing green hydrogen systems for ammonia fertilizer production, initially piloting the technology with solar power in Iowa and later targeting wind energy partnerships in Minnesota. Both HyWatts and other U.S. hydrogen companies are increasingly seeking international markets, with Talus Ag recently securing a partnership with PepsiCo for operations across Europe, Sub-Saharan Africa, and Asia Pacific regions. The technology continues to evolve as companies identify niche applications where hydrogen’s advantages in reliability and long-term storage can offset high production costs.