How ASICs enable reliable, efficient hydrogen fuel cell operation

The International Energy Agency predicts that hydrogen demand will surpass 100 metric tonnes in 2025, driven by increased use of hydrogen as a feedstock for industrial processes. Converting hydrogen into power is highly sensitive, relying on sensors to maintain stable, efficient operation. But harsh operating environments can degrade these sensor outputs. Here, Ross Turnbull explains how custom ICs address this challenge

Global demand for fertilisers, industrial chemicals and low-carbon steel is driving growth in energy-intensive sectors such as “refining, ammonia, methanol and fossil-based direct-reduced iron (DRI)”.

These processes require continuous, reliable electricity and heat to maintain production efficiency. To meet this demand while reducing reliance on non-renewable energy, industrial sites are increasingly turning to hydrogen fuel cells to generate power.

Hydrogen fuel cells produce electricity by splitting hydrogen molecules into protons and electrons. The positively charged protons pass through an electrolyte to a cathode, while the negatively charged electrons flow through an external circuit, creating an electric current. After passing through the electrolyte and circuit respectively, the electrons and protons meet at the cathode and combine with oxygen to produce water and heat, which can be captured to support chemical reactions, generate steam or heat plant facilities.

This reaction is extremely sensitive to changes in temperature, pressure, hydrogen concentration and fluid flow. To maintain safe and efficient operation, hydrogen fuel cells rely on a network of sensors that continuously monitor and regulate the process.

Sensor challenges

Temperature and pressure sensors monitor internal conditions, ensuring the cells remain within their optimal range of 50 to 100 degrees Celsius and one to three atmospheres, critical for stable electrochemical reactions. Hydrogen concentration sensors measure gas levels in real time, confirming sufficient fuel for consistent electricity and heat output, while fluid-level and flow sensors track the fuel cell separators, maintaining stability and preventing interruptions.

To produce usable, accurate data, these sensors rely on integrated functional blocks such as amplifiers, filters and analogue-to-digital converters (ADCs) to condition their analogue signals. These circuits stabilise measurements, remove electrical noise and convert raw outputs into a digital format suitable for system-level control.

Once conditioned, this data is transmitted to the fuel cell control system, where general-purpose processors, such as CPUs, analyse measurements, coordinate subsystems and adjust operating parameters. However, the accuracy and timing of these decisions depend heavily on the quality of the data received.

In harsh industrial environments, high humidity, elevated temperatures, pressure fluctuations, vibration and electromagnetic interference (EMI) can degrade signals before they reach the processor. To ensure reliable sensor performance when signal degradation is a risk, robust integrated circuits (ICs) designed for precise signal acquisition are essential.

The case for ASICs

Unlike general-purpose processors, ASICs are designed from the ground up to perform a specific set of functions within a defined operating environment, making them ideal for the precise demands of hydrogen fuel cells.

Rather than relying on separate components and high-level processing architectures, the full signal chain required for fuel cell monitoring can be integrated onto a single ASIC.  This approach delivers significant space savings while including all essential elements, including analogue front-end circuitry, amplifiers, ADCs and digital control logic tailored to the exact sensor types used. By consolidating these functions at the sensor interface, ASICs enable signal conditioning and conversion to occur close to the source, reducing susceptibility to electrical noise, minimising latency and improving data accuracy.

Integrating multiple functions onto a single chip also reduces processing overhead, allowing ASICs to consume less power than standard processors and reducing parasitic losses within the fuel cell system.

Fuel cell operation also demands reliable, real-time performance. Small deviations in operating conditions can quickly impact efficiency or damage the membrane, making predictable response times essential. ASICs offer unparalleled performance levels compared to CPUs operating in the same task space. Benefitting from fixed digital logic, ASICs are designed for a specific application, meaning for identical inputs under identical operating conditions they always output the same response. This enables faster, more consistent control responses to changing operating conditions, supporting stable electricity and heat output.

Finally, ASICs can be engineered for environmental resilience, tolerating elevated temperatures, high humidity and EMI, with built-in compensation for thermal drift, component ageing, and long-term parameter variation.

As hydrogen is increasingly adopted as an energy source, the reliability and efficiency of hydrogen fuel cells become critical. Purpose-built ASICs enable precise, reliable sensor processing under harsh conditions, supporting stable fuel cell operation and helping hydrogen scale as a viable industrial energy solution.

Ross Turnbull, Director of Business Development at application-specific integrated circuits (ASIC) specialist Swindon Silicon Systems.