Technology · PEM Hydrogen Fuel Cells

Low-cost hydrogen power for the grid, road, and sky.

PEM fuel cells are a proven technology. Protonas's contribution is making them affordable — through stack design, cooling architecture, and manufacturing choices aimed at real-world price points.

Cross-section of a PEM fuel cell: hydrogen enters the anode, protons cross the membrane, electrons flow through the external circuit as usable DC power, and water exits the cathode.
PEM CELL — CROSS-SECTION BYPRODUCT: PURE WATER

How it works

Four steps from hydrogen to electricity.

A PEM (proton exchange membrane) fuel cell is an electrochemical device: it converts fuel to electricity directly, without combustion. That directness is why it reaches up to 2 times the efficiency of burning the same fuel — and why its only exhaust is water.

Single cells are stacked in series to build voltage, and the stack is sized to the job: hundreds of watts for a drone, kilowatts for a telecom site or a delivery vehicle.

  1. Hydrogen meets the anode

    H₂ flows into channels in the anode plate, where a catalyst splits each molecule into protons and electrons.

  2. The membrane sorts them

    The polymer membrane passes protons through to the cathode — but blocks electrons.

  3. Electrons take the long way

    Blocked by the membrane, electrons travel through the external circuit instead. That detour is the electrical current that powers your load.

  4. Water leaves the cathode

    At the cathode, protons, electrons, and oxygen from the air recombine. The product is pure water — the cell's only byproduct.

Design philosophy

Cost is a spec, not an afterthought.

Fuel cells have historically been priced for aerospace and showcase projects. Protonas engineers to a different target: the price at which a telecom operator, a fleet owner, or a drone manufacturer says yes.

  • Part-count reduction — every component must earn its place
  • Manufacturing processes selected for scale, not for the lab
  • Manufacturing in Bangalore, India — close to key markets
  • Designs developed for drone, backup, and vehicle duty cycles
vs. diesel generatorsNo combustion, no point-of-use emissions, far fewer moving parts
vs. battery-only backupRuntime limited by fuel supply, not cell chemistry — designed for 8–72 hours
vs. battery swaps (drones)Battery packs last 200–300 full discharge cycles; hydrogen refuels in minutes
vs. grid charging (fleets)Refueling in minutes keeps vehicles earning instead of waiting

Want the engineering conversation?

Tell us about your power requirements, duty cycle, and environment — our stack team reads every inquiry.