Discover Siltrax's C2 Series hydrogen fuel cell with closed-cathode design, targeting UAV and off-grid power markets with 2–6kW output across Asia-Pacific.
Siltrax, a Sydney-based hydrogen technology company, has brought its C2 Series hydrogen fuel cell platform to market, targeting commercial UAV operators, portable power users, and off-grid energy applications with a system that delivers between 2 and 6 kilowatts of output. The company says the launch responds to growing demand from field operators who need longer run times and higher payload capacity without the weight penalties and mechanical overhead associated with existing power solutions.
Customer integration programs and partner demonstrations are already active across the Asia-Pacific region. Siltrax has also scheduled an exhibition of the C2 Series at the Hydrogen Technology World Expo at Hamburg Messe in Germany, running from 20 to 22 October 2026, where the company will be at Stand 7F30-5.
The distinguishing technical claim Siltrax makes for the C2 Series centres on its closed-cathode architecture, which the company describes as a deliberate departure from the open-cathode approach common in most air-cooled fuel cell systems. In a conventional open-cathode design, the same airflow that cools the stack also supplies oxygen to the cathode, meaning the cathode is directly exposed to whatever contaminants or variability exist in the surrounding air.
The C2 separates those two functions entirely. In the closed-cathode configuration, dedicated fans drive ambient air through cooling channels in the stack while the cathode reactant-air supply is channelled independently. That separation allows the oxygen flow, pressure, and filtration to be managed and controlled in isolation from the external environment. Siltrax said this results in measurable gains in both performance and system durability. The third architectural element is dead-end anode operation, which supports efficient hydrogen utilisation while removing the need for a continuously running hydrogen-recirculation circuit.
Siltrax said this choice further reduces balance-of-plant weight and the number of moving components the operator must maintain. Underpinning all three design choices are the company's proprietary silicon bipolar plates. Siltrax described itself as a firm that has built its technology on 40 years of silicon expertise, and the silicon bipolar plate is central to its product lines across transportation, distributed power, material handling, and related sectors. The company said the plates enable a compact form factor that achieves competitive power density without requiring a liquid-cooling circuit.
Daniel Zafir, Director of Business Development and Global Partnerships at Siltrax, said the customer conversations driving the C2 development have consistently returned to two requirements: longer operating times and greater payload capacity, both without adding unnecessary weight or mechanical complexity. He described the C2 as bringing together the silicon bipolar-plate technology and the purpose-built air-cooled architecture to produce a platform suited to exactly those demands.
Siltrax positioned the C2 as a direct response to the battery-electric limitations being encountered by operators deploying commercial and industrial UAVs for logistics, infrastructure inspection, agriculture, and similarly demanding use cases. As flight-duration and payload requirements have grown, battery propulsion has run into practical constraints that the company argues hydrogen fuel cells can address. Outside of UAV propulsion, Siltrax said the C2 Series is equally applicable to portable power systems and off-grid energy deployments where conventional liquid-cooled fuel cell systems carry weight and maintenance burdens that are unworkable in field conditions. Remote power installations, mobile generators, and autonomous systems are among the use cases the company cited.
The C2 Series spans a power output range of 2 kW to 6 kW. Siltrax has defined a 3 kW configuration as the reference architecture for customer evaluation and initial application integration work. The rated power for the platform is listed at 3.6 kW, with a gravimetric power density exceeding 1.5 kW per kilogram. For applications that require more capacity, C2 Series modules can be operated in parallel, allowing combined output of up to 24 kW. The system is rated for ambient operating temperatures from negative 20 degrees Celsius to 40 degrees Celsius, a range designed to accommodate the varied environmental conditions encountered in field deployments.
The C2 Series launch follows a separate commercialisation initiative Siltrax announced in September 2026 covering the Americas, through which the company established a presence across that region. The C2 launch represents the next step in what Siltrax describes as a broader expansion of its commercial footprint and customer partnerships internationally. The company is headquartered in Sydney and has not disclosed the names of customers currently participating in the integration programs and demonstrations underway in the Asia-Pacific region, though it confirmed those programs are already active. Siltrax said it is accepting inquiries for product specifications and evaluation opportunities through its commercial contact channels.
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