How Does a Fuel Cell Work?

A PEM fuel cell is the reverse of a PEM electrolyzer: hydrogen (H₂) enters at the anode, oxygen (or air) enters at the cathode, and electricity is produced as protons move through the membrane and electrons flow through an external circuit.

The only "exhaust" is water (H₂O) — no CO₂, no NOx, no particulates. This is why fuel cells are attractive for applications where emissions, noise, or vibration create problems: telecommunications towers, hospitals, data centres, indoor forklifts, submarines, and drones.

Key advantage over batteries: Fuel cells can be refuelled in minutes (like a petrol vehicle) whereas batteries require hours to recharge. For long-duration backup power and high-utilisation mobile applications, this is decisive.

Types of Fuel Cells and Their Applications

PEM Fuel Cell (PEMFC) — The Versatile Workhorse

Operates at 60–80°C, starts up in seconds, and works with high-purity hydrogen (99.97%+). This is the dominant technology for mobile and backup power applications.

Shakti Photon Solutions range: 1W (lab bench) to 400kW (industrial)

SOFC (Solid Oxide Fuel Cell) — For Large Stationary Use

Operates at 600–1000°C, can run on natural gas or hydrogen, and achieves very high efficiency (60%+). Best for large, continuous power generation where the long start-up time (hours) is acceptable. Not in Shakti Photon's current product range.

Application Guide: Which Power Range for What?

ApplicationPower RangeKey Requirements
Lab research / testing1W – 100WPrecise current/voltage control, safety enclosure
Drones (VTOL, fixed-wing)200W – 5kWHigh power density, lightweight, >2 hour flight time
Residential backup power1kW – 10kWSilent, low maintenance, 48–72 hour autonomy
Telecom towers (off-grid)2kW – 15kWUnattended operation, wide temperature range
Industrial backup (hospitals, data centres)50kW – 200kWInstant startup, parallel operation, grid-sync
Buses, trucks (heavy transport)80kW – 400kWHigh durability (20,000+ hours), fast refuelling
Train / locomotive200kW – 1.2MWMultiple stack integration, regenerative braking

Fuel Cells in India: Where the Adoption Is Happening

Telecom Off-Grid Power

India has approximately 600,000 telecom towers, of which roughly 200,000 are in off-grid or weak-grid areas. Diesel gensets currently power most of these — at high fuel cost, high maintenance cost, and high carbon footprint. Hydrogen fuel cells offer a compelling alternative where green hydrogen can be supplied by a local electrolyzer or hydrogen delivery network.

This is one of the largest near-term markets for fuel cells in India, and several pilot deployments are underway.

Drones and Unmanned Aerial Vehicles

Battery-powered drones are limited to 20–40 minute flight times. Hydrogen fuel cell drones achieve 2–5 hours of flight on the same weight payload, making them viable for surveillance, agriculture spraying, delivery, and infrastructure inspection at scale.

India's defence and civilian drone market is growing rapidly. DRDO and several private companies are actively developing hydrogen drone programmes.

Hydrogen Trains

Indian Railways has announced plans for hydrogen-powered trains on non-electrified routes. This is a large-scale application (200kW–1.2MW per train) that is expected to deploy in the late 2020s, creating significant demand for domestically manufactured fuel cell systems.

Backup Power for Critical Infrastructure

Hospitals, data centres, and government facilities that cannot tolerate power outages are evaluating hydrogen fuel cells as an alternative to diesel generators for long-duration backup (>8 hours) where battery storage is uneconomical.

Key Considerations for Deploying Fuel Cells in India

Hydrogen Supply and Storage

A fuel cell system is only as good as its hydrogen supply chain. Options in India:

  • On-site electrolyzer: Pair a PEM electrolyzer with the fuel cell for a complete off-grid power system. Shakti Photon Solutions offers integrated electrolyzer + fuel cell systems.
  • Hydrogen cylinder delivery: Available but expensive (₹300–600/kg delivered) and requires PESO-licensed storage
  • Hydrogen pipeline: Only available in certain industrial clusters; not yet widespread in India

Regulatory Requirements

Hydrogen storage and use in India falls under the Petroleum and Explosives Safety Organisation (PESO) regulations. Any installation storing >1 kg of hydrogen requires PESO licensing. This is well-established for industrial applications but adds lead time to project planning.

Humidity and Temperature

India's humid climate (particularly coastal regions like Chennai) requires careful fuel cell membrane management. Nafion membranes need to maintain optimal hydration — our systems include active humidification and temperature management for Indian climate conditions.

The Integrated Approach: Electrolyzer + Fuel Cell

The most powerful deployment of fuel cell technology in India is as part of an integrated green energy system:

  1. Solar panels generate electricity during the day
  2. PEM electrolyzer converts excess solar electricity into hydrogen (stored as compressed gas)
  3. PEM fuel cell converts stored hydrogen back to electricity at night or on cloudy days

Round-trip efficiency is approximately 40–50% (lower than batteries) — but the key advantage is long-duration storage. While batteries degrade rapidly for >8 hour storage, hydrogen can store energy for weeks or months with minimal losses.

This makes the electrolyzer + fuel cell pair the technology of choice for truly off-grid systems: remote telecom towers, island power, and seasonal energy storage at large scale.

Designing a fuel cell system for your application?

Whether you're a drone manufacturer, a telecom operator, or a plant engineer looking for diesel genset replacement — our team will recommend the right system and integration approach for your specific conditions.

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